plant selection for harsh urban environments

Plant Selection for Harsh Urban Environments in the Phoenix/Tempe Area

A Thesis Study by Erin Torchia, Candidate for Bachelor’s Degree of Science in Land-scape Architecture at Arizona State University

ABSTRACT This project seeks to provide Landscape Architects practicing in the Phoenix/Tempe area of Arizona with a guide to assist with the process of selecting plants for harsh urban environments in the region. The first step was an online survey of professionals in the area, to determine which urban conditions were harsh, followed by interviews with consenting survey respondents to determine why each condition was harsh, which plants belong in it, and what sites in the study area are good examples of well-planted areas in harsh con-ditions. The final product is an essay (detailing the research methods and findings of the study), a set of case studies that visually document some of the sites suggested by survey respondents, and a set of plant lists for each harsh urban situation.

A Note of Thanks I would like to thank my thesis Director, Rebecca Fish Ewan, and my Sec-ond Chair, James Coffman for all their encouragement, guidance, and patience. I would also like to thank my external reviewers, Caryn Logan Heaps and Judy Mielke, whose plant knowledge was indispensable, and those who responded to the survey, particularly those who consented to be interviewed (listed below). I appreciate the time each interviewee took to speak with me and share their hard-earned knowledge. There were several professionals who consented to be interviewed, but whom I did not have enough time to speak with; I am grateful

that they were willing to donate their time to my cause.

Aaron AllanAdam Hawkins

Caryn Logan HeapsDean ChambersDenise Dunlop Jack GilmoreJim Coffman

Judy MielkeKristian KelleyLaura ThelenRoger Socha

Shari ZimmermanSteve VollmerTodd Briggs

Above: Ruellia peninsularis bloom, found at Phoenix City Hall (shrubs in streetscape on western side of building). Left, Top: The roof of the Tempe Transportation Center, as seen from halfway up the trail on “A” Mountain (Tempe Butte). Left, Bottom Left: Agave desmettiana found on the south side of Arizona Center, in an at-grade planter with widely spread out Palm Trees Elf Aloes, and other accent plants. Left, Bottom Right: Chilopsis linearis found in bloom at the Veteran’s Way Light Rail Station, receiving full sun on the station platform.

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INTRODUCTION This project began with a plant identification class, taken in the spring semester of my third year at Ar-izona State University. I discovered, as our class roamed the campus in search of commonly used plants, that I was fascinated by the notion that plants belonged in certain spots and not in others. I never gave it a second thought before that class: every plant in my designs was placed where I wanted it (for its color, shade, shape, etc.), with no regard to the needs of the plant. I learned that each plant had its own preferences with regard to soil and water (which didn’t come as a surprise), and could be affected by the reflected light and heat of the buildings and surfaces around it. I began to wonder if there was a guide to show me the way when choosing plants for my designs. I found quite a few landscape architecture-oriented plant books, and most of them had recommendations for each plant about how much heat and water the plant could take. Some books went so far as to provide suggestions for the plants’ aesthetic uses; some plants could “soften” a landscape, while others looked best when planted in clumps. These comments helped immensely, but I was looking for a book that could point me in the right direction when it came to specific recurring microclimates, like parking lots and rooftop gardens. The climate in Phoenix, Arizona tends to be very hot, and the city suffers greatly from the Urban Heat Island Effect. Thus, common features of the urban fabric tend to be more harsh and unforgiving to plants as a result of this- even the desert-adapted plants struggle to cope with the extreme conditions. I couldn’t find any sources to enlighten me about how to choose plants for these particularly difficult situations, or even a source to explain which factors made the situations difficult in the first place. Thus, I set out to find out which factors made a given urban situation challenging to choose plants for, and which plants belonged in each situation.

LITERATURE REVIEW I began my literary research with a search of the library database for any and all books related to plant selection and identification. Professor Fish Ewan suggested several very helpful books, one of which was written by one of the practitioners I later interviewed (Judy Mielke). Each book I found had plant pictures or sketches (which were slightly less helpful) and information about the plants’ growth habits and preferences. Most were organized by general plant type (tree, shrub, vine, groundcover, etc.), and then alphabetically by botanical name within each section. These types of books were examined both for their information and the quality of the layout. They did not seem to contain information about where in a specific design each plant be-longed, with relation to the common urban environments that made up most of the urban fabric; though there were some very helpful comments about where plants belonged in terms of design aesthetics and function. The plant books also tended to cover some basic pruning practices and common pest problems, which I did not plan to include within the scope of this study. I analyzed which layouts were graphically clear and easy to read, and which layouts did not utilize their white space well. I found that the books with pictures that were not aligned with one another or the text were much less aesthetically pleasing than those that had a single or small set of layouts that were consistent throughout the book. I was originally going to create plant pages from my project, but I was told during my thesis defense that most Landscape Architects already had scores of plant books taking over their desks. I was encouraged to emphasize my case studies (explained below) instead, as these would be entirely new content (rather than content that attempted to reinvent the wheel in terms of plant information books).

Above Left: Texas Ebony tree (Ebenopsis ebano) on the east side of the Fulton parking structure on ASU Tempe campus; photo taken in plant identification class (Spring 2014). Above Right: Opuntia macrocentra var. violaca-ea, growing on the south side of a building on the ASU Tempe campus (photo taken in same plant class, Spring 2014). Right: Some of the books used for research; mostly from the ASU libraries, with a couple (not pictured) from the North Valley Regional Library in Anthem, AZ.

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4RESEARCH

Research: Methods | SURVEY

The research began with a survey, followed by interviews with respondents to clarify their answers. The results of the survey and in-terviews were then analyzed and extrapolated into charts and case studies. The first step was to create a survey to determine which urban situations were difficult to choose plants for and why. The survey was set up with SurveyMonkey.com, because it was easy to use and free; it was also a trusted source so survey-takers didn’t have to worry about following questionable links. I decided it was important to keep the survey short, so that participants could take it in 15 minutes or less (to increase the chances of getting responses from busy professionals). I also looked at the number of swipes it would take to read the email and take the survey on the standard smartphone; most people seem to check their emails on their phones rather than carrying bulky lap-tops. The introductory email (Appendix A) required 2 swipes, while the final form of the survey (Appendix B) could be read with 3-4 swipes. The first two questions dealt with what factors made a particular ur-ban situation “difficult” to choose plants for in the mind of the land-scape architecture professional. Question 1 asked participants to rate 9 factors according to their importance in terms of plant selection. The categories were “extremely important”, “very important”, “moderate-ly important”, “somewhat important”, and “unimportant”. The factors

were access to water, level of shade, heat mitigation, wind, solar ori-entation, physical space limitations, soil conditions, regulation of plant palette, and heat radiated/reflected from surrounding surfaces. There was an “other” category as well, which allowed respondents to spec-ify another factor and rate it. The physical space limitations category was meant to bring to mind physically constrained conditions (such as the planter spaces in parking lots and streetscapes), as well as constraints imposed by utility clearances (such as overhead electrical lines). The “level of shade” category referred to shade created by the building or by other vegetation; “solar orientation”, however, referred to which side of the building the planting was on (East, West, etc.). Professor Fish-Ewan and I then came up with a list of com-mon situations that could be difficult to find plants for; we knew that not all designers would agree on which conditions were challenging, so it was a rather long list. We shortened it down to the following twelve, and added an ‘other’ option in case the survey-takers thought of something we missed. The east, west, north, and south sides of buildings were each given their own category, yielding four situations. These conditions were meant to cover the foundation plantings and plantings within several feet of the building, though there was no set dimension for this. The idea was that plants that sat on each side of a given building would not be shaded by adjacent buildings and (generally) would not face solar glare either- the main factor affecting these situations would be solar exposure. Courtyards made up the next two categories, and were divided into at-grade versus sunken (4 feet below grade or lower). The ‘sunken courtyard’ category was originally going to be an ‘urban canyon’ category, but most of the buildings in Phoenix and Tempe are not tall enough to create a true

urban canyon (such as those that would be created in New York City). Parking lots were given a category of their own, as were rooftops. Rooftops are not typically planted, but the trend toward green roofs has reached Phoenix and there is interest in both types of rooftop plantings. Extensive plantings are generally considered to have 6” of soil or less and are not meant to be maintained; intensive plantings, however, feature soils 8” or deeper and are used as rooftop gardens where people can gather. The exact type of roof planting was not specified for the purposes of this survey, simply because it would have increased the complexity and the time needed to take it. This category was expected to have mixed results, because the climate here has proved challenging so far for those attempting green roofs. Streets-capes made up the next category, and the term was used to indicate the plantings in the medians of streets as well as those along the sides of the streets. The last three categories were parks, residential areas, and retention basins. Both the parks category and the residential category were left rather unspecified – respondents were not given direction regarding programming, size, or price range in order to gar-ner a larger number of responses. If they had been further defined, they would have taken up far more than two categories and run the risk of being skipped by respondents who might not have expertise with such a specific situation. Both categories were expected to be fairly easy to choose plants for, but were included to gather statistical data and discern why they would be easy. The final category, reten-tion basins, was suggested by one of my instructors, Kristian Kelley. He pointed out that they are a very common urban situation, as they are found on most commercial sites and used to deal with storm water. The survey was created and opened on October 30, 2014,

65%

35%

Survey Response Rate

Responses received

Participants who did NOTanswer

83%

17%

Survey Responses- Percentage of Respondents who Consented to an Interview

Consented

Declined

48%

21%

31%

Respondents to be Interviewed

Have Been Interviewed

Will NOT be Interviewed(Unidentifiable)

Have not beenInterviewed YET

There are 178 active, licensed Landscape Architects in the Phoe-nix/Tempe Area, and the survey was sent to 54 of them (30.3%). Source: Arizona State Board of Technical Registration website.

5 and it was in a trial phase for the first month. This meant that the link to the survey was only given to a handful of my teachers (and my thesis director) so they could take it and give me feedback about the layout and verbiage of the questions. These responses were deleted (as they were not yet statistically relevant) and the survey was modified and improved. A list of firms in the Phoenix/Tempe area was compiled from a combination of Google.com searches and Professor Fish Ewan’s contact list of ASU alums, and a spreadsheet was created to house all pertinent data about each firm. The spreadsheet included space for contact information, as well as boxes to indicate when the survey was sent, who responded, and when each respondent would be inter-viewed. The introductory email, containing the link to the survey, was sent to the majority of the firms on February 1, 2015. The rest of the firms (there were only a few) had to be called for an email address; some firms did not have any contact info and were therefore omitted from the study. A second email (Appendix C), politely reminding firms who did not respond to the survey, was sent approximately 10-15 days later (it took a few days to sort through responses to determine who had answered). It contained a brief description of why they were receiving the email, as well as a link to the survey to eliminate the need to sort through their inbox to find the original email. This yielded quite a few more responses, much to my delight. The survey has not been officially closed, but I stopped receiving responses on April 1, 2015, and did not send any more reminder emails. Responses were digitally saved, and files were named with the re-spondent number, the date the response was received, and the name of the respondent, if it could be found. The SurveyMonkey interface provided an excellent interface for this; I could examine each response

individually or view the charts compiled automatically for the aggre-gate data. Unfortunately, I couldn’t export either the responses or the charts to my computer from the website, because that would require a paid subscription. I was unwilling to pay, but I found a way around the limitation: I simply clicked on my browser’s “print” button and sent the documents to be printed via pdf (portable document format), which left me with digital files for my records. I entered the rest of the data into Microsoft Excel by hand, and created my own charts with that program. This method ended up being more effective anyway, be-cause I could edit the colors and format of each graph, as well as create a host of additional charts and graphs for more detailed trend analysis.

Research Methods | INTERVIEW

The interview questions were developed by my thesis director and I, and began as a small, three-question follow-up to the ques-tionnaire. However, as I began receiving survey results, I considered the notion of asking the interviewees what specific plants they would use for each situation, as this was the information I was seeking. I did not want to simply create a form for the interviewees to fill out about the matter, because that did not seem interactive enough for an in-terview, particularly with people who had already taken the time to complete a survey for me. I ended up creating interview forms for one professional who consented to be interviewed but didn’t have time to meet with me; he was extremely kind and filled out the entire 3-page form and emailed it back promptly. I also created an interview form for Professor Coffman (the second chair on my review board for the

project), who only had time to meet with me for half the time of the interview. The other questions initially slated for the interviews were general questions about why each interviewee had responded to the survey with the answers they provided; I printed all the survey results and brought a copy with me when I went to the interviews, to avoid incon-veniencing the interviewees by asking them to try to remember their answers. Proposed questions included, “what makes one urban situa-tion more difficult than another,” and “what types of desert-adapted plants do you typically place in these situations?” I also planned to ask for general advice for beginning landscape architects, but the interviews tended to fill up the entire hour allotted, so that question was left unasked. Instead, I focused on asking why each person had considered each situation difficult or easy, though at first I only asked for explanations of why a given situation was difficult. I discovered, however, that the logic behind the classification of a site as “easy” was equally important: some professionals only considered a situa-tion easy because they had a specific list of plants to use, or they had a lot of experience with that particular urban condition. I also modified the questions of the interview between interviews, because the discussions brought up some points that I had not thought to ask. These questions related to which plants the professionals considered “bulletproof” or “overused” and which plants they enjoyed or hated using. I also began to ask for specific plants for each of the situations, a brief explanation of why each situation was difficult or easy, and a quick review of their opinions on each case study suggested in the survey. Interviewees were shown a printed list (color coded to delin-eate between sites in Phoenix and sites in Tempe) of the case studies

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Question 6 of the survey asked about how long each respondent had been practicing in the area; it was interesting to note that there were no practitioners who had worked in the area for 21-25 years (left). The chart to the right demon-strates the same information, separated with different time frames; there is still a large decrease in the number of peo-ple who have been working here for 20-29 years.

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55%33%

7%5%

Case Study Sites Suggested by Respondents

Sites in Phoenix

Sites in Tempe

Sites in Scottsdale

Sites in OtherCities in Arizona

(well-planted areas in harsh urban situations) suggested by survey respondents and asked what they thought of each site. There was a map provided of the sites in Downtown Phoenix, to help them locate and hopefully recall details about the areas. The queries about bullet-proof, overused, and preferred plants stemmed from the interviews at one particular firm; the professionals I interviewed had mentioned that they avoided certain plants because the way they tended to be installed and maintained shortened the lifespan.

Research Methods | CASE STUDIES

Survey respondents were asked, in Question 4 of the survey, to provide examples of “sites within the Phoenix/Tempe area [that] would be good examples of well-designed planting plans in difficult places”. The resulting list was 38 items long, and some of the items included multiple sites. I had intended to visit all the sites suggested when I started the survey, but I knew I couldn’t manage the task when I reviewed the entire list. I decided to eliminate the sites that were outside the Phoenix/Tempe area because they wouldn’t be statistical-ly relevant for this study (though they would be useful as a general source). The suggestions that were too vague or included too many sites, such as “anything by Christy Ten Eyck,” “anything by Steve Mar-tino,” or “all LRT stations” were also excluded. (I did make a point of visiting as many Light Rail stations as I could, since some of them fell in the study area.) Some sites, such as the Desert Botanical Garden and Galvin Parkway, were eliminated as well because they simply weren’t considered “harsh urban environments”. This still left approximately 28 sites on the list, so I began scheduling visits on days where I had sev-eral hours free at a time. I then mapped the remaining sites in Phoenix and Tempe, and plotted the best routes between them using Google Maps. I was also working on scheduling the interviews at the time, so I mapped those as well. Typically, I would use the time before, after, or between interviews to visit sites; I also visited sites before my studio class, which was in the afternoon on Wednesdays and Fridays. Thus, the sites cho-sen tended to be clustered together in either Downtown Phoenix or Tempe. I will eventually visit all the sites, but due to the time constraints of the project, I was only able to visit and document twelve of the thirty-eight sites. The sites in Tempe were: Mill Avenue (between Uni-versity Drive on the south end and 3rd Street on the north end), the Light Rail stations at 3rd Street and Veterans Way, the Tempe Trans-portation Center, the ASU Institute of Religion, and the ASU Biodesign building and adjacent sunken garden. Mill Avenue was moderately easy to photograph, though it was difficult (as it is in all public spac-

es) to take photos without making other people feel uncomfortable... Most of the photos taken in the Tempe sites were taken in the mid to late afternoon, typically outside of peak pedestrian traffic times. The sites in Downtown Phoenix were the Cancer Survivor’s Park (a medi-an on a calm street), the Phoenix Art Museum, CityScape courtyard, Phoenix City Hall, Phoenix Municipal Court, and the Arizona Center. These sites were typically visited in the morning or early afternoon; I had only visited one site (CityScape) prior to this project. The sites in Phoenix were accessed by car, and therefore the LRT stations in the area were not documented (due to the time constraints of metered parking). Once sites had been chosen, I set out to document them with my camera and a notebook. I should have added a comfortable pair of shoes to my list of travel gear, but I frequently had to schedule the site visits on days when I interviewed professionals for this project. I therefore spent several hours documenting harsh urban conditions in Phoenix and Tempe in high heels and dress clothes, and once had to walk across the bottom of Tempe Butte because there was no side-walk available. Nonetheless, the sites visited provided a wealth of information about plants that could survive harsh conditions. The case studies included with this document do not represent the full docu-mentation effort; only four sites were included due to some changes in format, suggested at my thesis defense. The other case studies will be formatted and included with the digital booklet sent out to the professionals who were kind enough to grant me interviews.

• Phoenix Convention Center• Civic Space Park• Scottsdale Museum of the West• Estrella Hall at Estrella Mountain Community College• Downtown Tempe• Downtown Phoenix• Scottsdale• Kornegay building• GateWay Community College• Hayden Square (Tempe)• Adams St. at 3rd St. (Phoenix)• All LRT stations• Downtown Central Ave. in Phoenix• ASU Biodesign builidng• Tempe Metro Transit Stations• ASU Institute of Religion• “Anything by Christy Ten Eyck”• “Anything by Steve Martino”• University Streetscape project in Tempe (West of Mill Ave)• Monroe Ave Streetscape Project in Buckeye 5th - 7th Street• Phoenix City Hall• Phoenix Municipal Courthouse• CityScape Courtyard• Cancer Survivor’s Park• Chaparral Water Treatment Plant• Tempe Transit Center• ASU Downtown Campus• Taylor Street Mall• Maricopa County Downtown Courts• ASU ISTB IV (new interdisciplinary building just south of the Biode-

sign building)• Phoenix SkyTrain 44th Street Station and Eas Economy Lot (EEL)

Station• Phoenix Art Museum• Arizona Center• Oak Trees on Ash Avenue• Mill Avenue• Galvin Parkway• Sunken Garden at ASU (on the east side of the Biodesign building)• Desert Botanical Garden

LIST OF CASE STUDIES SUGGESTED

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Case Studies suggested in survey

Case Studies suggested indirectly (ie: “anything by Christy Ten Eyck / Steve Martino”)

Sites are superimposed over a Valley Metro map of all LRT stations because they were suggested as case studies

Case Study CategoriesThe sites visited (listed on the right) can be divided up into 4 categories: Bulding/Buildings, Courtyards, Light Rail Stations, and Streetscapes. The first category, “Building/Buildings,” encom-passes those sites whose primary feature is the landscape around a single building or set of buildings that are related to one another. Courtyards include the sites whose emphasis is upon the space between a set of buildings that is open to the sky and intended to be inhabited by people; Light Rail Stations include the station platform only. The final category, “Streets-capes,” is a bit more tricky. It typically includes the streetside plantings (such as those beside the public sidewalks) and the median, one is present - though for the purposes of this study, it also includes the Cancer Survivor’s “Park” which takes up residence entirely within a median. All spaces visited were publicly accessible.

• Phoenix City Hall 200 W. Washington Street Phoenix, AZ, 85003

• Phoenix Municipal Court-house

300 W. Washington Street Phoenix, AZ, 85003

• CityScape Courtyard 11 W. Washington Street Phoenix, AZ, 85004

• Cancer Survivor’s Park 1428 N. 1st Street Phoenix, AZ, 85004

• Phoenix Art Museum 1625 N. Central Avenue Phoenix, AZ, 85004

• Arizona Center 400 E. Van Buren Street Phoenix, AZ, 85004

• Mill Avenue Between University Drive and 3rd Street Tempe, AZ, 85281

• Mill Ave. & 3rd St. LRT Sta-tion

Tempe, AZ, 85281

• Veterans Way LRT Station Tempe, AZ, 85281

• Tempe Transit Center 200 E. 5th Street Tempe, AZ, 85281

• ASU Biodesign Institute 1001 S. McAllister Avenue

Tempe. AZ, 85281

• ASU Institute of Religion 1000 S. McAllister Avenue Tempe, AZ, 85281

RESEARCH: FINDINGSQUESTIONS 1 & 2

Questions 1 and 2 were intended to determine which factors made an urban environment harsh for plants, and wich of these fac-tors were most important when choosing plants for a harsh urban environment. The results of Question 1 are shown on this page, both collected into a single chart (below) and broken into separate pie charts by factor. It was unsurprising that “access to water” was the most import-ant factor, considering the location of the study area (the Phoenix/Tempe regions of Arizona). Water conservation and wise usage of water are constantly encountered issues in Phoenix and Tempe, be-cause both fall within the Lower Colorado River Valley area of the Sonoran Desert, which is quite arid. It was also unsurprising that “so-lar orientation” and “physical space limitations” were noted as being very important factors, as the plant’s size and sun tolerance are com-monly noted items in plant identification books. The most surprising trend was how many of the professionals surveyed said that wind

was “moderately important”. Wind tolerance is almost never mentioned in plant identification books, and yet practitioners reported that it de-served moderate consideration. This may be due to the fact that wind from cars and other vehicles can be very intense along streetscapes; perhaps the professionals surveyed worked on a lot of streetscapes, or

found themselves dealing with them because both Phoenix and Tempe are largely auto-centric. Many of the people interviewed said they ranked various fac-tors as being “less important” because said factors (like soil conditions) were relatively easy to amend.

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Relative Importance of Factors that Make an Urban Situation "Harsh"

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Soil Conditions

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Unimportant

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Heat Radiated or Reflected from Surrounding Surfaces

Extremely Important

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Somewhat Important

Unimportant

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14%

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Heat Radiated or Reflected from Surrounding Surfaces

Extremely Important

Very Important


Somewhat Important

Unimportant

24%

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27%

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Heat Mitigation

Extremely Important

Very Important


Somewhat Important

Unimportant

43%

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Solar Orientation

Extremely Important

Very Important


Somewhat Important

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Most Important Factoraccess to water

soil conditions

heat mitigation

physical space limitations

regulation of plant palette

solar orientation

level of shade

radiated/ reflected heat

Other

20%

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9%

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Second Most Important Factor

access to water

soil conditions

heat mitigation



solar orientation

level of shade

heat radiated or reflected fromsurrounding surfacesOther

20%

12%

3%

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12%

9%

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Second Most Important Factor

access to water

soil conditions

heat mitigation



solar orientation

level of shade

heat radiated or reflected fromsurrounding surfacesOther

access towater

soilconditions

heatmitigation

physicalspace

limitations

regulationof plantpalette

solarorientatio

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level ofshade

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heatOther

Most Important Factor 12 5 1 7 2 3 1 0 3Second Most Important Factor 7 4 1 5 0 7 4 3 3Third Most Important Factor 3 3 0 7 2 6 4 3 6

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Factors that make an Urban Situation "Harsh" Question 2 was meant to determine which factors were most important, of the factors provid-ed in Question 1. The answers were fairly consistent with those found in the first question, though there were still some interesting trends. The first puzzling trend was how few people said heat mitigation was an important factor; this may be because most of the native plants are quite adept at dealing with heat, and most of the professionals in the study area tend to gravitate toward using native plants. The second surprising trend was how few respondents consid-ered “regulation of plant palette” to be an important factor. This may be because the question might not have been specific enough; some people may have interpreted it as referring to the clients’ preference (which they may have felt was negotiable), or local regulations such as those that control streetscape plantings. As it turns out, these are surprisingly nego-tiable too... Mill Avenue is currently planted with Ficus trees, which are prohibited in public right-of-ways (be-cause they are not water-efficient). This was a result of a rather sneaky move: the area in question was re-zoned as a park, which did not have the same restrictions. The last notable trend was the relative-

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Commonly Encountered Urban Situations

Level of Difficulty (Regarding Plant Selection) for Common Urban Environments

EasyModerately EasyNeutralDifficultVery Difficult

ly large percentage of professionals who included “other”factors. Some of these factors included safe-ty (most commonly associated with the dangers of thorny plants), and maintenance (a topic all on its own).

The survey results will be discussed here in detail, and each urban condition is discussed with re-gard to both its survey results and the comments made

in the interview. Each section also includes a list of plants recommended for that particular situation, with small images of the plants. Resources for finding more

information about plants (such as their growth habits and requirements) can be found in the index. The chart above shows the survey results for Question 3.

RESEARCH: FINDINGSQUESTION 3

9

10

Grass-Lined retention basin at Tempe Beach Park (after a rainstorm)

Courtyard within an apartment complex in Tempe

View of the Mill Avenue streetscape and Median in Tempe (near University Drive)

Rooftop green space on the Tempe Tran-sit Center, near Forest Ave. & 5th St.

South Side of a building in Downtown Phoenix (Washington St. and Central Ave.)

West side of the Bank of America building on 2nd St. and Washington St. (Phoenix)

North side of a church on Lawrence Rd. near 19th Ave. (Phoenix)

East side of building in Scottsdale Quarter complex (just north of splash pad area)

Tiny courtyard/ramp leading down to the Design South basement (ASU Tempe)

Parking Lot near a library in Avondale; found at 4th St. and Western Ave.

The illustration at left is meant to be a generic guide to visualizing the ‘harsh urban environments’ studied in the survey. Parks and residential areas have been left out because they were found not to be considered harsh for plants, though they are discussed at the end. The pic-tures provided are examples of each sit-uation, and may not exactly match the diagram in terms of scale or relationships to nearby buildings; they typically do not depict the sites in the case studies. Shad-ows in both the diagram at left and the diagram close-ups for each situation are set for 2:15 pm on November 8th.

1. Retention Basins (pg 11)2. Courtyards (pg 12)3. Streetscapes (pg 13)4. Rooftop Gardens/Green Roofs (pg 14)5. South Sides of Buildings (pg 15)6. West Sides of Buildings (pg 16)7. North Sides of Buildings (pg 17)8. East Sides of Buildings (pg 18)9. Sunken Courtyards (pg 19)10. Parking Lots (pg 20)

9

10

3

1

2

46 8

7

5

9 10

31 2 4

6 87

5

RETENTION BASINS- Retention basins are typically lined with decomposed granite of various sizes (depending upon the location of the basin and the expected velocity of water flowing into it), or turf. The rock treatments must be chosen so that they can be large enough to prevent erosion, but rocks this size tend to trap more water and this results in a plant with soggy roots (a condition which most desert trees

despise). Nonetheless, these were generally considered to be easy because there were few restrictions on the size of planting spaces, no pedestrian or vehicular activity, and tended to be left more natural. These areas don’t have to look pruned and picturesque at all times of the day and year, though they are subject to periodic flooding and the collection of contaminants (from runoff water) that can sometimes

turn the decomposed granite black. . Thus, plants that can’t handle such flooding (such as Saguaros) don’t belong there, though there are plenty of drought tolerant plants that won’t mind. These areas were also considered easy because there are several lists available that disclose which plants will do best in these conditions.

34%

41%

19%

3% 3%

Retention Basins

Easy

Moderately Easy

Neutral

Difficult

Very Difficult

PLANT CHARACTERISTICS TO LOOK FOR • Drought tolerant• Tolerant of periodic flooding• Tolerant of soil contaminants (depending upon the location of the

basin)• Provision of erosion control• If in an area frequented by humans (ie: a grassy basin in a park),

consider choosing thornless plants

Acacia redolens (Prostrate Acacia)

Photo taken at Arizona State University, Tem-pe Campus, in parking lot north of Design North building, Spring 2014

Grasses (ie: Muhlenbergia capillaris, Gulf Muhly)

Photo taken in Desert Botanical Garden, March 23rd, 2013

These plants were recommended by practicing professionals during the interview sessions. Several suggested planting the bottoms of retention basins with grasses or riparian plants, and the edges with more tropical plants. One practitioner mentioned a new trend to-ward leaving the bottoms bare and adding plants to the sides (to achieve a more natural aesthetic, modeled after the riparian corri-dors of the desert).

Tecoma Stans(Yellow Bells)

Photo taken at CityScape courtyard, Spring 2015

RECOMMENDED PLANTS- City of Scottsdale

The following native plants are recommended by the City of Scotts-dale for use in retention and detention basins. Please see Appendix D for the exact page of the source document, which was recommed-ed by several of the practitioners interviewed.

Plants for the bottom:

• Velvet Mesquite (Prosopis velutina)• Four-wing Saltbush (Atriplex canescens)• Desert Hackberry (Celtis pallida)• Catclaw (Acacia greggii)*• Scrub Oak (Quercus turbinella)*• Chuparosa (Justicia californica)• Canyon Ragweed (Ambrosia ambrosioides)

Plants for the sides:

(All plants listed above)• Ironwood (Olneya tesota)• Blue Palo Verde (Cercidium floridum)• Desert Willow (Chilopsis linearis)• Saguaro (Carnegiea gigantea)

• Wolfberry (Lycium Sp.)• Desert Lavender (Hyptis emoryi)• Fairy Duster (Calliandra eriophylla)• Creosote (Larrea tridentata)• Jojoba (Simmondsia chinensis)*• Hopbush (Dodonaea viscosa)*• Mormon Tea (Ephedra trifurca)*• Cheese Bush (Hymenoclea monogyra)• Deer-Vetch (Lotus rigida)*• Sugar Sumac (Rhus ovata)*

Plants to avoid in any part of the basin:

Foothills Palo Verde (Cercidium microphylla)• Chollas and Pricklypears (Opuntia Sp.)• Barrel Cacti (Ferocactus Sp.)• Bursage (Ambrosia deltoidea)• Century plants (Agave Sp.)• Brittlebush (Encelia farinosa)• Buckwheat (Eriogonum fasciculatum)• Ocotillo (Fouquieria splendens)

Professionals interviewed also recommended that Saguaros (Carne-giea gigantea) be avoided because they do not appreciate having soggy roots.

20%

43%

17%

20%

0%

Courtyards

Easy

Moderately Easy

Neutral

Difficult

Very Difficult

11

COURTYARDS- Most respondents reported courtyards as being moderately easy, and only 7 people found them to be difficult. No one considered them ‘very difficult’ to choose plants for. Courtyards tended to have borrowed shade (noted in the interviews as an asset), and a lot of paving (which would cause reflected heat) combined with

pedestrian traffic that might make it necessary to find plants that can withstand a bit of trampling. One interviewee said he liked putting a tree in the center of smaller courtyards to provide shade for the entire space, while another recommended potted plants. Many of the pro-fessionals interviewed noted that each courtyard was different, and

it was a bit difficult to generalize. Courtyards that face west or south, for instance, would face a lot of reflected heat, while courtyards that faced north might have to cope with extra shade.

PLANT CHARACTERISTICS TO LOOK FOR • Shade tolerant• Tolerant of pedestrian use (& occasional trampling)• Tolerant of reflected heat (from buildings and paving)• Tolerant of life in a container, in some cases (some courtyards

have potted plants)• Pleasantly aromatic• Aesthetically pleasing in color, form, or both

20%

43%

17%

20%

0%

Courtyards

Easy

Moderately Easy

Neutral

Difficult

Very Difficult

These plants were recommended by practicing professionals during the interview sessions. Many of the interviewees did not specify an exact species, merely a Genus (such as Ruellia) or a type of plant

(such as a vine). The emphasis seemed to be on providing shade and creating a space where humans could interact with the plants on a more intimate level than is typical for public spaces. For instance, one

practitioner recommended aromatic plants, and many chose plants that had interesting blooms. and would be soft to the touch.

RECOMMENDED PLANTS

Ruellias- unspecified species

Both Ruellia brittoniana and Ruellia penin-sularis are typical in Phoenix; photo is of a Ruellia brittoniana in the parking lot of the Phoenix Art Museum (taken Spring 2015)

Mesquites- unspecified spe-cies

Photo taken in Desert Botanical Garden, March 2nd, 2013

Green Walls- unspecified composition

Photo taken in the Desert Botanical Garden, Spring 2015

Dermatophyllum secundiflorum (Texas Mountain Laurel)

Photo taken in northern Phoenix in a residen-tial backyard in Spring 2015

Lavendula species(Lavender)

I did NOT take this photo- it came from a blog called The Garden Glove

Vines- unspecified species

Photo is of a vine on the Veteran’s Way Light Rail Station, taken Spring 2015; common vine species for Phoenix are Bougainvillea, Lady Banks Rose, and Coral Vine

Tara cacalaco(Cascalote Tree)

Photo taken at Arizona State University, Tem-pe Campus, Spring 2014

Olneya tesota(Ironwood)

Photo taken in northern Phoenix in a residen-tial backyard in Spring 2015

Parkinsonia x ‘Desert Museum’(Desert Museum)

Photo taken at Singh Farms, Spring 2015

12

STREETSCAPES- These tended to be rated as moderately easy (37%), though 20% of respondents considered them difficult and 14% considered them very difficult. Those who said they were relatively easy explained in the interviews that they frequently dealt with street-scapes. The main issues with streetscapes are reflected heat (particu-larly from the paving), pedestrian trampling, wind from passing cars, limited planting spaces, regulations (typically from a city or district), and maintenance. The pedestrian abuse was typically confined to the plantings near sidewalks (rather than those in street medians), and the limited planting space was almost always a problem – small planting spaces are not ideal for trees intended to be 15-25 feet tall. Utility and vehicular clearances were a perpetual issue: telephone wires could not have trees that grew up to touch them, so the trees would either be stunted or pruned around the wires. (It should be noted that this practice occurs all over Phoenix and looks quite ridiculous, in addition

to being a health hazard to the tree.) Maintenance crews would also shear the plants to leave right-of-ways clear (such as those needed by passing trucks to avoid hitting tree canopies), but the plants’ health was not considered, and the crews never tried to prune the poor trees back into their natural shapes. This too can be seen through-out Phoenix and Tempe – many street trees have suspiciously square cutouts in their canopies on the side that faces the street. The last pruning practice discussed was the tendency to prune desert trees into single-trunk trees with excessively high and thin canopies. Mainte-nance crews consider this a good thing, based on the theory that the monsoon winds will pass through the branches more easily instead of uprooting the tree. However, these trees end up acting as umbrellas- the wind can easily gain access under the high canopy, which then catches the wind and pulls the tree over. The proper way to deal with this would be to allow the trees to be more shrub-like, which would direct the wind over them instead of underneath them. Overwater-

ing was an issue as well for the desert trees- they have evolved to survive on very little water, and the regular irrigation causes them to grow much faster on the top. This is problematic, because it leads to the need for more pruning, and results in a tree with a canopy too heavy for its roots to anchor. The roots tend to stay where the easily accessible water is instead of spreading out like they would under normal circumstances; theoretically, this can be solved with concentric rings of irrigation. This rarely occurs, and maintenance crews do not seem to know or care about the proper amount of water required for a desert tree versus a tree from a more temperate climate. The issue of regulation turned out to be a minor issue when the interview-ees explained that they could simply work from the list of acceptable plants for a given streetscape, rather than attempting to figure out on their own what would grow. The professionals interviewed also cau-tioned against trees that branch or sucker from the bottom, as well as multi-trunked specimens planted in pedestrian areas.

PLANT CHARACTERISTICS TO LOOK FOR • Drought tolerant• Tolerant of pedestrian use (& occasional trampling)• Tolerant of reflected heat (from buildings, paving, & asphalt)• Non-Allergenic (airborne pollen is an allergy hazard and is typi-

cally discouraged in public spaces)• Thornless (to prevent public entity liability from pedestrian injury)

OR thorny enough to discourage pedestrian use of an area• Aesthetically pleasing all or most of the time• Able to cope with current maintenance practices• Tolerant of tight planting spaces (horizontally and vertically)

These plants were recommended by practicing professionals during the interview sessions; they had a lot to say about streetscapes.

Therefore, the pictures are smaller to accomodate the greater num-ber of recommended plants.

RECOMMENDED PLANTS

12%

37%

17%

20%

14%

Streetscapes

Easy

Moderately Easy

Neutral

Difficult

Very Difficult

Pistacia chinensis(Chinese Pistache)Photo taken at ASU Tempe cam-pus, Spring 2015

Oaks- unspecified speciesPhoto taken at CityScape, Spring 2015; most likely a Quercus virgini-ana (Southern Live Oak)

Ash- unspecified speciesPhoto of a Fraxinus veluntina (Arizona Ash) taken at the Phoenix Historic Homesteads park, 2014

Hesperaloe parviflora ‘Perpa’(Brakelights Red Yucca)I did NOT take this photo- it came from the Monrovia website

Previously Pictured Recommended Plants:

Mesquites, unspecified species (picture on pg 12)Grasses, unspecified species (picture on pg 11)Prostrate Acacia (Acacia redolens, picture on pg 11)

The following plants generally should NOT be used: Ironwood, Agaves, Aloes, and Cacti (unless used on a street with vehicular speeds low enough to pro-mote visibility, or they will be underappreciated).

Sages- unspecified speciesPhoto of a Leucophyllum frutescens ‘Compacta’, taken in a residential backyard in Phoenix, 2013

Palo Verdes- unspecified speciesPhoto of a Parkinsonia preacox taken at ASU Tempe campus, 2014

Lantana- unspecified speciesPhoto of a Lantana camara taken at ASU Tempe campus, Spring 2014

Phoenix dactylifera(Date Palm)Photo taken at the Arizona Cen-ter, Spring 2015

Aloe x ‘Blue Elf’(Blue Elf Aloe)Photo taken at ASU Tempe cam-pus, Spring 2014

Ulmus parvifolia(Chinese Elm)Photo taken near the Tempe City Hall, Spring 2014

13

0%

20%

11%

40%

29%

Rooftops

Easy

Moderately Easy

Neutral

Difficult

Very Difficult

PLANT CHARACTERISTICS TO LOOK FOR • Drought tolerant• Tolerant of pedestrian use (not all situations)• Tolerant of direct sun & hot soil• Tolerant of shallow soils• Attracts wildlife (typically desireable, but may be limited in areas

where people gather)• Aesthetically pleasing all or most of the time (in some cases)• Able to survive on rainwater (if left to fend for itself)• Tolerant of tight planting spaces (if planted in a pot on the roof

or in small trays placed on the roof)

The professionals interviewed recommended plants for rooftops based on the approach they took to designing them and the desired end result. Roof gardens, which are meant to be inhabited by humans, tend to be carefully designed and feature flowers and shrubs, with the occassional tree. Trees are not a common element (particularly

RECOMMENDED PLANTS

Larrea tridentata(Creosote)Photo taken at in Goodyear near the landfill, Fall 2014.

Hesperaloe parvifloraPhoto taken at the ASU Tempe campus, Spring 2014

Simmondsia chinensis(Jojoba bush)Photo taken at the Phoenix Art Museum, Spring 2015

Dasylirion acrotrichum(Green Desert Spoon)Photo taken at the University Dr. & Rural Rd. LRT station, Spring 2014

Pachycereus marginatus(Mexican Fence Post Cactus) I did NOT take this photo- it came from the University of Arizona

Cacti- unspecified speciesPhoto of a variety of cacti at the Desert Botanical Garden, March 2nd, 2013

Succulents- unspecified spe-cies (generally mixed)Photo taken at the Desert Botani-cal Garden, Spring 2015

Olea europaea ‘Montra’(Dwarf Olive, “Little Ollie”)I did NOT take this photo- it came from the Monrovia website

Euphorbia lomelii(Lady’s Slipper)Photo taken at ASU Tempe cam-pus, Spring 2014

Prickly Pear- unspecified speciesPhoto of Opuntia microdasys at the Desert Botanical Garden

in our climate) in roof gardens because they require at least 24-36 inches of soil, and the structural modifications required are not cheap. The second common approach to rooftop plantings is the “green roof” method, where the desired result is a rooftop covered in plants but inaccessible to humans. This method, in turn, yields two types of re-sults: the first is the typical green roof, planted with low-water-use succulents and other aesthetically pleasing plants, and the second

is a rooftop covered in native plants and left as habitat for birds and other winged creatures. That type of roof is not trimmed or necessarily irrigated, and can be found on the rooftops of county park buildings. The aesthetically pleasing green roofs are meant to be viewed from above, and tend to be maintained accordingly. They can be found on roofs between taller buildings or have their own viewing platforms. Both types of green roofs should avoid Candelilla, which tends to die.

“Meadow Mix”- unspecified mixed species of wildflowersPhoto taken at Boyce Thomp-son Arboretum, March 2013

Previously Pictured Recommended Plants:Lantana- unspecified species (pg 12)Grasses- unspecified species (pg 11)

14ROOFTOPS- Rooftops were considered difficulty by 40% of survey respondents, 29% considered it very difficult, and 20% considered it moderately easy. Only 11% considered them neutral, and not one re-spondent said they were easy. This turned out to be a reasonable con-clusion when the challenges associated with rooftop gardens were explained in the interviews. Firstly, there are structural issues with add-ing large loads to rooftops – most buildings are not designed to carry extra loads, and soil, plant matter, and the associated water are all very heavy. Lighter soils can be engineered (typically called planting mediums), and shallower soil depths are used. This limits the size of the

plants, both in terms of available space and available soil for roots to grow in. These thin and lightweight soils don’t hold water like normal soils do, so the plants dry out faster as well – a problem amplified by the scorching temperatures of Phoenix, which bake the soil. The low volume of soil means that it changes temperature more quickly than deeper soils, which translates to hotter roots. Thus, rooftop plantings are essentially large, shallow planter pots. Drainage also becomes an issue, because most dry land plants tend to fare poorly when their roots are constantly saturated in water. Unfortunately, the water cannot simply drain onto the roof, because that is the area most vul-nerable to leaks (into the building); therefore, drainage systems must

be devised to handle the water (pumps are required to get it up to the rooftop in the first place) to get the water off the rooftop and into other areas of the site or into the sewers or storm drains. Some inter-viewees felt that rooftops were not the right place to be looking for planting space because the options on the ground plane had yet to be exhausted. Many people commented that rooftop gardens were only merited if the designer was trying to create a space for people to inhabit. Rooftop plantings that were included purely to gain LEED points tended to have cheap, thin plants that did not fare well in the long term, whereas rooftop gardens were more carefully designed.

SOUTH SIDES OF BUILDINGS- The main concern here was heat. Solar gain was inevitable, but reflected heat from the surface of the building also had to be considered when choosing plants for this area. Fifteen respondents considered this exposure ‘moderately easy’

to work with, however, because our native Sonoran Desert plants are quite accustomed to harsh sun and high soil temperatures. Only one respondent considered it ‘very difficult’, and noted in the interview that this was because the heat and light could reach beneath the

canopy (because of the sun’s angle in the afternoon) and negatively affect the plants’ health. This respondent also viewed west sides and parking lots as being very difficult and difficult, respectively, though the rest of the situations seemed to be rated ‘neutral’ or easier.

31%

43%

14%

9%

3%

South Sides of Buildings

Easy

Moderately Easy

Neutral

Difficult

Very Difficult

PLANT CHARACTERISTICS TO LOOK FOR • Drought tolerant• Tolerant of pedestrian use (not all situations)• Tolerant of direct sun & hot soil• Able to provide shade for the building (trees)• Tolerant of reflected heat (from building or, in some cases, from

other buildings, paving, and asphalt)• Aesthetically pleasing all or most of the time (in some cases)

These plants were recommended by practicing professionals during the interview sessions. They had no trouble listing plants that belonged on the south sides of buildings; it resulted in one of the longest plant

lists provided. The plants listed tend to be desert adapted; many are Sonoran Desert natives, and a fair amount come from Australia.

RECOMMENDED PLANTS

Senna (AKA Cassia) speciesSenna didymobotrya pictured, photo taken at ASU Tempe cam-pus in secret garden, Spring 2014

Ericameria laricifolia(Turpentine Bush)I did NOT take this photo- it is from the Sonoran Desert Naturalist

Senna artemisiodes(Feathery Senna)I did NOT take this photo- it is from the Swinburne Image Bank

Desert Spoons- unspecified-speciesPhoto of Dasylirion longissimum taken at the Desert Botanical Garden, Spring 2015

Eremophila maculata ‘Valen-tine’ (Red Emu Bush)Photo taken at ASU Tempe campus, Spring 2014

Previously Pictured Recommended Plants:Lantana- unspecified species (pg 12)Mesquites, unspecified species (pg 12)Olneya tesota (Ironwood, pg 12)Tecoma stans (Yellow Bells, pg 11)Simondsia chinensis (Jojoba, pg 14)Olea europaea ‘Montra’ (Dwarf Olive, pg 14)Leucophyllums- unspecified species (pg 13)

The following plants should NOT be placed on the south side of a building: Agaves and Aloes. These plants require a bit of shade, and southern exposures are typically a bit too harsh for them. However, if they are planted beneath trees or placed where they will receive shelter from the late afternoon sun, they may be able to survive.

Encelia farinosa(Brittlebush) Photo taken at the Desert Botani-cal Garden, Spring 2015

Alyogyne huegelii(Blue Hibiscus)I did NOT take this photo- it’s from the Arizona Cooperative Exten-sion

Calliandra callifornica(Baja Fairy Duster)I did NOT take this photo- it is from the Southern Water Authority

Chilopsis linearis(Desert Willow)Photo taken at ASU Tempe cam-pus, Spring 2014.

Hesperaloe x ‘Pink Parade’(Pink Parade)I did NOT take this photo- it is from a nursery called The Greenery

Caesalpinia pulcherrima(Mexican Bird of Paradise)Photo taken at ASU Tempe cam-pus, Spring 2014

Sphagneticola trilobata

(Yellow Dot)Photo taken at the ASU Tempe campus, Spring 2014

Carissa macrocarpa(Natal Plum)Photo taken at the ASU Tempe campus, Spring 2014

Lysiloma speciesPhoto taken at the ASU Tempe campus, on the southwest corner of the Design South bulding, 2014

Dodonaea viscosa(Hopseed Bush)Photo taken at the ASU Tempe campus, Spring 2014

Muhlenbergia rigens(Deer Grass)I did NOT take this photo- it is from San Marcos Growers

15

WEST SIDES OF BUILDINGS- Heat was a major concern here, but the intensity of the afternoon sun was the biggest issue. Plants that normally liked heat would sometimes suffer sunscald, which is like the arboreal version of sunburn. The sun’s low afternoon angle would

allow it to burn the trunks, since the light would come in beneath the (normally protective) leafy canopy. Some respondents considered it a challenge to find plants that could tolerate the conditions, but others considered it fairly easy – typically because they chose native plants

which grew in harsh desert environments. It seemed that respondents tended to consider it moderately easy or difficult, with only a few giving it a rating of neutral (7 people) and only 5 people total rated it extremely easy or extremely difficult.

12%

31%

20%

34%

3%

West Sides of Buildings

Easy

Moderately Easy

Neutral

Difficult

Very Difficult

PLANT CHARACTERISTICS TO LOOK FOR • Drought tolerant• Tolerant of pedestrian use (not all situations)• Tolerant of intense direct sun & hot soil• Aesthetically pleasing all or most of the time (in some cases)• Able to provide shade for the building (trees)• Tolerant of reflected heat (from building or, in some cases, from

other buildings, paving, and asphalt)

The three in the column below were newly mentioned, while the pic-tures below show pictures of plants from the “South Sides of Buildings” list that were also specifically mentioned for western exposures. Prac-titioners also mentioned that succulents and elms could be placed

RECOMMENDED PLANTS

Tecompa capensis (Cape Honeysuckle)

Photo taken ASU Tempe campus, on the western side of a parking garage, Spring 2014

Oleander-Unspecified spe-cies

Photo taken Summer 2014 at a historic home on Pinchot Ave. and 26th St.

Ruellia peninsularis(Desert Ruellia)

Photo taken at Phoenix City Hall on the northeast side, Spring 2015

Hesperaloe species(Red Yucca varieties)

Photo of Hesperaloe parviflora taken at Taliesin West, Feburary 19, 2014

Leucophyllums- unspecified species (Texas Sage varieties)

Photo of a Leucophyllum frutescens ‘Com-pacta’, taken in a residential backyard in Phoenix, 2013

Calliandra californica (Baja Fairy Duster)

I did NOT take this photo- it came from the Southern Water Authority website

Simmondsia chinensis(Jojoba bush)

Photo taken on ASU Tempe campus near the Fulton building, Spring 2014


Lantana- unspecified species (pg 12)Mesquites, unspecified species (pg 12)Olneya tesota (Ironwood, pg 12)Tecoma stans (Yellow Bells, pg 11)Olea europaea ‘Montra’ (Dwarf Olive, pg 14)

Plants from the South Sides list (pg 15):

Dodonaea viscosa (Hopseed Bush)Lysiloma speciesCaesalpinia pulcherrima (Mexican Bird of Paradise)Carissa macrocarpa (Natal Plum)Sphagneticola trilobata (Yellow Dot)Desert Spoons- unspecified speciesChilopsis linearis (Desert Willow)Encelia farinosa (Brittlebush) Alyogyne huegeli (Blue Hibiscus)Eremophila maculata ‘Valentine’ (Red Emu Bush)Senna (AKA Cassia) speciesEricameria laricifolia (Turpentine Bush)Muhlenbergia rigens (Deer Grass)

here, but must be sheltered from reflected heat. The following plants should NOT be placed on the south side of a building: Morning Glo-ries (Convolvulaceae family).

16

NORTH SIDES OF BUILDINGS- The main complaint here was that the solar exposure left the areas in deep shade for most of the year, including winter, but during the hottest part of summer the sun would peek over the building and essentially fry the plants. The soil also tended to stay wetter for a bit longer than in other exposures,

because of the increased shade. Professionals would have to choose plants that could stand deep shade (which decreased the tempera-ture in general and make area particularly cold in winter) while also retaining the capacity to cope with intense heat and sunlight during the summer months. The majority of professionals rated this situation

as being moderately easy, with ratings of ‘difficult’ and ‘neutral’ fol-lowing close behind. Surprisingly, only two people considered it easy, and six people considered it very difficult. They also noted that this exposure produces plants with fewer blooms, so they tended to use interesting forms and textures to create visual interest.

PLANT CHARACTERISTICS TO LOOK FOR • Drought tolerant, but also capable of handling slightly damper

conditions• Tolerant of pedestrian use (not all situations)• Shade tolerant • Cold and Frost Hardy• Aesthetically pleasing all or most of the time (in some cases)• Interesting form to compensate for reduced quantity of blooms• Tolerant of reflected heat (from building or, in some cases, from


6%

28%

23%

26%

17%

North Sides of Buildings

Easy

Moderately Easy

Neutral

Difficult

Very Difficult

Ilex- unspecified species(Holly Species)I did NOT take this photo- it came from FloraFinder.com

Sansevieria species(Snake Plant)I did NOT take this photo- it is from the OnlinePlantGuide.com

Myrtus communis ‘Compacta’(Compact Myrtle)Photo taken at ASU Tempe cam-pus, Spring 2014

Pittosporum tobira(Mock Orange)Photo taken at ASU Tempe campus, Spring 2014

Previously Pictured Recommended Plants:Grasses- Muhlenbergia rigens (Deer Grass) and other bunch grasses (pgs 11 & 15)Dermatophyllum secundiflorum (Texas Mountain Lau-rel, pg 12)Hesperaloes- unspecified species (pg 16)Dodonaea viscosa (Hopseed Bush, pg 15)Carissa macrocarpa (Natal Plum, pg 15)

Rhaphiolepis species(Indian Hawthorn)I did NOT take this photo- it is of a Snow Cap variety from Cross Creek Nursery

Lantana montevidensis(Trailing Lantana)Photo taken in Tempe, Spring 2014

Justicia spicigera(Mexican Honeysuckle) Photo taken at the ASU Tempe campus, Spring 2014

Buxus sempirvirens(Boxwood, multiple species)Photo taken at the Arizona Cen-ter in Spring 2015

Dietes iridioides(African Iris, Morea Iris)Photo taken at the Arizona Cen-ter in Spring 2015

Citrus aurantium(Orange Tree)Photo taken at ASU Tempe cam-pus, Spring 2014.

Vinca major ‘Variegata’(Greater Periwinkle)I did NOT take this photo- it came from Plantify.co.uk

Ruellia brittoniana ‘Katie’

(Katie Ruellia)I did NOT take this photo- it came from the Dave’s Garden website

Ficus pumila(Creeping Fig)Photo taken at the ASU Tempe campus, Spring 2014

Rosmarinus officinalis(Rosemary)Photo taken at the ASU Tempe campus, Spring 2015

Aloe vera(True Aloe)Photo taken at the ASU Tempe campus, Spring 2014

Agave desmettiana(Dwarf Century Plant)Photo of variegated specimen tak-en at Arizona Center, Spring 2015

Verbena- unspecified speciesI did NOT take this photo- it is from GardenBanter.co.uk

The professionals interviewed recommended a very wide variety of

RECOMMENDED PLANTS plants for this urban situation. In addition to the plants listed below, they suggested Aloes, Agaves, and Vines in general, and Asparagus Ferns. The following Asparagus Ferns were specifically mentioned: the

Ming Fern, the Foxtail Fern, and the Sprengerii Asparagus Fern. The following plants should NOT be placed on the south side of a building: turf, Geraniums, Ruellia peninsularis (Baja Ruellia), due to excess shade.

Trixis- unspecified speciesPictured: Trixis CalifornicaI did NOT take this photo- it is from Delange.org

17

EAST SIDES OF BUILDINGS- These situation seemed to be ideal; interviewees had very little trouble getting plants to grow here. Most of them commented that they could get the widest variety of species to grow there, and as such did not feel they faced a limited

plant palette. This exposure had just the right amount of exposure- the morning sun provided gentle light, while the building itself provided shade from the intensely hot afternoon sun. No one rated it as being ‘very difficult’, but one person did rate it as being difficult. This per-

son also rated courtyards and residential areas as being difficult, and north sides, parking lots, and streetscapes as being very difficult to choose plants for. Unfortunately, this person declined an interview, so I was unable to ask them for an in-depth explanation.

26%

57%

14%

3% 0%

East Sides of Buildings

Easy

Moderately Easy

Neutral

Difficult

Very Difficult

PLANT CHARACTERISTICS TO LOOK FOR • Drought tolerant• Tolerant of pedestrian use (not all situations)• Aesthetically pleasing all or most of the time (in some cases)• Tolerant of reflected heat (from building or, in some cases, from


Asparagus densiflorus ‘Mey-ersii’ (Foxtail Fern)

Photo taken near the ASU Institute of Reli-gion (Tempe), Spring 2014

Hesperaloe species(Red Yucca varieties)

Photo of Hesperaloe parviflora taken at Taliesin West, Feburary 19, 2014

There were only two plants specifically mentioned for the eastern exposures, which are pictured. The professionals also said that this exposure would yield almost any plant, and the recommended plant

list was a combination of the plants for the northern and southern exposures.

RECOMMENDED PLANTS

Previously Pictured Recommended Plants- South Sides:

Caesalpinia pulcherrima (Mexican Bird of Paradise pg 15)Calliandra callifornica (Baja Fairy Duster pg 15)Carissa macrocarpa (Natal Plum pg 15)Chilopsis linearis (Desert Willow pg 15)Dermatophyllum secundiflorum (Texas Mountain Laurel, pg 12)Desert Spoons- unspecified species pg 15Dodonaea viscosa (Hopseed Bush, pg 15)Encelia farinosa (Brittlebush pg 15) Grasses- Muhlenbergia rigens (Deer Grass) and other bunch grass-es (pgs 11 & 15)Hesperaloes- unspecified species (pg 16)Lantana- unspecified species (pg 12)Leucophyllums- unspecified species (pg 13)Lysiloma speciesSimmondsia chinensis (Jojoba, pg 14)Sphagneticola trilobata (Yellow Dot pg 15)

Previously Pictured Recommended Plants- North Sides:

Agave bracteosa (Candelabrum Agave/Squid Agave)Agave desmettiana (Dwarf Century Plant, pg 17)Aloe vera (True Aloe pg 17)Alyogyne huegeli (Blue Hibiscus pg 15)Asparagus densiflorus ‘Sprengerii’

Asparagus macawaniiBuxus sempirvirens (Boxwood, multiple species, pg 17)Citrus aurantium (Orange Tree pg 17)Dietes iridioides (African Iris, Morea Iris pg 17)Eremophila maculata ‘Valentine’ (Red Emu Bush pg 15)Ericameria laricifolia (Turpentine Bush)Ficus pumila (Creeping Fig pg 17)Ilex- unspecified species (Holly, pg 17)Justicia spicigera (Mexican Honeysuckle pg 17)Lantana montevidensis (Trailing Lantana pg 17)Mesquites, unspecified species (pg 12)Myrtus communis ‘Compacta’ (Compact Myrtle, pg 17)Olea europaea ‘Montra’ (Dwarf Olive, pg 14)Olneya tesota (Ironwood, pg 12)Pittosporum tobira (Mock Orange, pg 17)Rhaphiolepis species (Indian Hawthorn, pg 17)Rosmarinus officinalis (Rosemary pg 17)Ruellia brittoniana ‘Katie’ (Katie Ruellia pg 17)Sansevieria species (Snake Plant, pg 17)Senna (AKA Cassia) species pg Tecoma stans (Yellow Bells, pg 11)Trixis- unspecified species (American Threefold, pg 17)Verbena-unspecified species, pg 17Vinca major ‘Variegata’ (Greater Periwinkle pg 17)Vines, unspecified species

Jasmine species

I did NOT take this photo- it came from a website called the Gardenista

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SUNKEN COURTYARDS- Many of the professionals inter-viewed said they would shy away from designing these, citing safe-ty as the controlling factor. Apparently, when an enclosed space is sunken that far below street level, it becomes problematic in terms of supervision – in short, it creates “rape corners”. These small areas are out of the sight lines of the pedestrians on the street and generally the people in surrounding buildings as well, which allows criminals to hide there unnoticed. Additionally, people who get trapped would have a hard time escaping, because a 4 foot grade change is difficult to climb over quickly. Overall, the sunken courtyard seems to have

been phased out in most situations, and one interviewee noted that “they were more popular in the 70’s”. The actual planting conditions, however, don’t seem to pose much of a challenge. Only 4 people reported that they were ‘difficult’, while all others rated them as being ‘neutral’ or easier in terms of choosing plants. The main challenge seemed to be the additional shade (though it is worth noting that not every sunken courtyard is shaded), typically provided by surrounding buildings or trees. Lower temperatures also occur at the bottom of such courtyards, which means that plants must cope with more shade and cooler air and soil; this is more of a challenge in winter. The last

factor, mentioned by only one interviewee, was the lack of topsoil. This person noted that the lower grade typically required digging down into the subsoil (plants prefer to grow in topsoil), and sometimes this will result in reaching caliche. Caliche is a bit like concrete – though it forms naturally when a layer of “soil particles are cemented together by lime,” it is not beneficial to the plants in the area. It essentially forms a nearly impermeable barrier that restricts water movement and root penetration. It also contributes to iron deficiency in the plants, which “causes yellowing in the youngest plant leaves” which can be wors-ened with increased irrigation.

3%

46%

40%

11%

0%

Sunken Courtyards (4 feet below grade or lower)

Easy

Moderately Easy

Neutral

Difficult

Very Difficult

PLANT CHARACTERISTICS TO LOOK FOR • Drought tolerant, but also capable of handling slightly damper

conditions• Tolerant of pedestrian use (not all situations)• Shade tolerant • Accents should be low, and plants should allow for good visibility• Cold and Frost Hardy (in very shady conditions)• Aesthetically pleasing all or most of the time (in some cases)• Tolerant of reflected heat (from building or, in some cases, from

other buildings, paving, and asphalt)• Should NOT provide hiding spots

Most of the plants recommended were low-growing to prevent safety issues, or fragrant and eye-catching to entice the pedestrians who use the space.

RECOMMENDED PLANTS

Platanus occidentalis(Sycamore)

I did NOT take this photo- it is from the Image Archive of Central Texas Plants

Cottonwood- unspecified species

Photo of Populus fremontii taken at the ASU Tempe campus, Spring 2014. Specimen was removed Spring 2015, fate unknown

Washingtonia- unspecified species

Photo of Washingtonia robusta, taken at ASU Tempe campus, Spring 2014

Dalbergia sissoo(Indian Rosewood)

Photo taken at the ASU Tempe campus, Spring 2014; please note that these trees are SLIGHTLY INVASIVE- so use with caution

Mesquite- unspecified species

Photo of a Prosopis glandulosa, taken at the ASU Tempe campus, Spring 2014


Chilopsis linearis (Desert Willow, pg 15)Jasmine species (pg 18)Phoenix dactylifera (Date Palm, pg 13)Rosmarinus officinalis (Rosemary, pg 17)Sphagneticola trilobata (Yellow Dot pg 15)Riparian Trees (species unspecified; these can include Palo Verdes, Mesquites, and several others)Low Accents- these would be accents 3 feet high or less, typically around 18 inches high. The low height prevents them from being used as hiding spots.

The following plants should NOT be planted in sunken courtyards: Lysiloma species, Elms, and Ash trees.

19

17%

37%

6%

29%

11%

Parking Lots

Easy

Moderately Easy

Neutral

Difficult

Very Difficult

PARKING LOTS- The majority of survey respondents (54%) consid-ered parking lots easy or moderately easy, 29% considered them dif-ficult and while 11% considered them very difficult. The main concerns associated with these areas were reflected heat, limited planting spaces and pedestrian/vehicular trampling. Parking lot medians take a lot of pedestrian abuse, and plants cannot have thorns for safety reasons (unless the designer is attempting to use them as a deter-

rent, which yields mixed results). Some practitioners avoid understory plantings (such as shrubs or groundcovers) in the medians beside cars, simply to avoid losing the plants to carelessly opened car doors. The interviewees who considered parking lots to be easy or moderately easy to choose plants for tended to cite copious amounts of experi-ence with the situation as a reason for their elevated comfort level; others noted that there were some lists for parking lot plants, and the

native trees here tend to handle heat very well. The only complaint about using desert trees (such as Palo Verdes and mesquites) was that these trees want to be giant shrubs- they prefer their branches to droop to the ground and shade their trunks from the sun, rather than being pruned up into “lollipop trees” (a common term in the profession that refers to single-trunked trees pruned to have a relatively round and uniform canopy).

PLANT CHARACTERISTICS TO LOOK FOR • Drought tolerant• Tolerant of pedestrian use and trampling• Tolerant of trampling via car or car door• Tolerant of pollutants that might be in runoff from the asphalt• Thornless, unless used as a deterrant for a particular area• Aesthetically pleasing all or most of the time (in some cases)• Tolerant of being harshly pruned by maintenance crews• Tolerant of tight planting spaces (horizontally and vertically)• Tolerant of reflected heat (from building or, in some cases, from


Several of the interviewees pointed out the similarities between park-ing lots and streetscapes- both involve heavy vehicular and pedestri-an use, tight planting spaces, and a lot of reflected heat. Pedestrians frequently trundle through the planted medians, and cars tend to hang their front bumpers over planted areas unless there is a cement curb to prevent them. Runoff can contain oil, dirty water, and any of the other fluids that run through a car; pedestrian-created trash (plastic bags, soda cans, etc.) can also accumulate in these areas. Then, plants must contend with maintenance practices. Many lots are maintained by people who don’t understand or care about the proper way to prune a tree or shrub - and they tend to be armed with electric trimmers. This results in the usual “poodling”, which can also extend to plants that are typically spared the attention of maintenence crews, like Hesperaloe. (This is very unhealthy for the plants, and the dam-age takes a long time to heal.)

RECOMMENDED PLANTS

Quercus virginiana(Virginia Live Oak)

Photo taken October 22, 2013 in Tempe

Vachellia farnesiana(Sweet Acacia)

Photo taken at Phoenix Pediatric Dental, February 11, 2015

Acacias- unspecified species

Photo of Acacia aneura, taken at a house on Lawrence Road near 21st Avenue, Febru-ary 11, 2015

Elms-unspecified speciesRecommended for dirt lots

Photo taken near Tempe City Hall, Spring 2014


Lantana- unspecified species (pg 12)Leucophyllums- unspecified species (pg 13)Mesquites, unspecified species (pg 12)Oaks- unspecified species Palo Verdes- unspecified species (pg 13Parkinsonia x ‘Desert Museum’ (Desert Museum, pg 12)Rosmarinus officinalis (Rosemary pg 17)Simmondsia chinensis (Jojoba, pg 14)Sphagneticola trilobata (Yellow Dot pg 15)

The following plants should NOT be planted in parking lots:

Echinocactus grusonii (Golden Barrel) Cholla species (far too thorny for pedestrian areas)Olneya tesota- not a bad parking lot tree, but tends to be consid-ered too valuable and to slow-growing to place in parking lots

The following plants can be planted in parking lots, but will suffer in the summer heat:

Ash trees (unspecified species)Elm trees (unspecified species)

20

52%37%

11%

0% 0%

Parks

Easy

Moderately Easy

Neutral

Difficult

Very Difficult

44%

38%

12%

6%

0%

Residential Areas

Easy

Moderately Easy

Neutral

Difficult

Very Difficult

PARKS- None of the survey respondents considered parks difficult or very difficult and only 11% said that they were neutral. These spaces were so easy because the plants in parks are cared for, even with the pedestrian traffic. Thus, they were statistically not considered harsh environments, and excluded from the scope of my study.

RESIDENTIAL AREAS- Residential areas were considered easy (44%) and moderately easy (38%), and only 6% considered them dif-ficult. The professionals interviewed explained that there was a much greater freedom associated with choosing the plant palette for a residence- the only restrictions tended to be client preference and occasionally, Homeowners Associations. These plants also received a much higher level of care, either by a resident involved in gardening or by a hired maintenance crew (which still tended to prune the shrubs

into balls). There was, however, a continuum of care given, with plants in single-family residential settings receiving the most care and plants in large multifamily residential areas receiving much less care. The only downside that the interviewees mentioned was the occasional request to provide certain plants that weren’t water-efficient (ie: turf) or were disliked by the Landscape Architect (this varied widely, but tended to be tied to which plants the practitioner viewed as ‘over-used’).

Above: Survey results about the difficulty (or lack thereof) of choos-ing plants for parks.

Above, left: A white Orchid Tree in a park in Tempe; small park also contained turf and Chinese Pistache trees. Above, righ: An unidenti-

fied tree and turf beside a multifamily residence. Above: Survey results about the difficulty of choosing plants for residential areas.

ADDITIONAL NOTABLE TRENDS- The interviews and the survey yielded a lot of information, but these trends did not fit in any predefined category, though they are worth mentioning.

AVAILABILITY OF PLANTS AND WATER- Only “availability of water” was a category, but the Landscape Architect’s ability to secure a particular plant for a site is also a crucial element of the success of a designed site. Interviewees commented that they sometimes could not buy a desired plant from nurseries (either when they began the design or by the time the plan was approved). This tended to be more of an issue with large-scale sites and public projects. The other alternative was “contract growing,” where clients can pay nurseries to grow a certain plant for a project, but this option is rather expensive. Water availability is an issue for all projects in Phoenix, simply because it is a desert and water is scarce and therefore should be used wisely. Public projects tend to feature drought tolerant plants, and all of the practitioners interviewed valued water conservation – they tended to push for such plants in their private sector designs as well.

MAINTENANCE- Although ‘maintenance’ was not a defined cat-egory in the survey, it quickly became apparent in the interviews that it was a major factor in plant selection and occasionally the overall design. Every professional I spoke with had issues with current main-tenance practices. Not one of them appreciated having their shrubs pruned into balls or “trash can shapes”. Laura Thelen called the prac-tice “poodling,” which perfectly describes the problem: the shrubs get trimmed (generally with and electric trimmer) into bizarre shapes sim-ply for aesthetic purposes. However, Phoenix is not Versailles. Formal hedges and impromptu topiary does not belong here, and the desert shrubs don’t appreciate the harsh pruning either. Clearly, there is a lapse of communication between the land-scape architects and the maintenance people; the important ques-tion is how to bridge the gap. Some of the professionals I spoke with would actually ask the maintenance company (if they knew who would be maintaining a particular site) what plants the maintenance crews would kill. This approach resulted from an experience where the landscape architect in question had spoken with a maintenance crew about another landscape matter, and the crew had unapolo-

getically informed him that they were not going to maintain a partic-ular plant. The best solution may be two-part: maintenance compa-nies can give their input regarding what types of plants are difficult to maintain, and landscape architects could provide maintenance manuals to the maintenance crews. Landscape architects should understand that the goal of the maintenance crew is efficiency, com-bined with the need for visibility (it must look like the crew has been there, hence the ‘poodling’). Maintenance crews, however, must be educated about the designers’’ intent, to prevent them from stamping their own intent upon the site via harsh pruning. Many of the profes-sionals I interviewed had pointed out that simple manuals and easily operated systems would be the best way to get good results.

21

OVERUSED PLANTS- The plants pictured in the first column were considered “overused” in the Phoe-nix/Tempe area, though opinions vairied widely.

BULLETPROOF PLANTS- Unsurprisingly, some of these plants turn up in the “overused plants” list, simply because they are used so often for their dura-

bility. They tend to be desert adapted and water-effi-cient, though current irrigation practices do not really account for this.

FAVORITE PLANTS- These plants were listed as being favorites, but are by no means agreed upon by all professionals.

Quercus virginiana(Southern Live Oak)Photo taken in Tempe, October 22, 2013

Agaves- unspecified speciesPhoto of Agave bovicornuta, taken at the Desert Botanical Garden, Spring 2014

Quercus fusiformis(Escarpment Live Oak)Photo taken at ASU Tempe cam-pus, Spring 2014

Mariosousa willardiana(Palo Blanco)Photo taken at ASU Tempe cam-pus, Spring 2014

Olneya tesota(Ironwood) Photo taken in North Phoenix backyard, Spring 2015

Parkinsonia x ‘Desert Museum’ (Desert Museum Palo Verde)Photo taken at Singh Farms, Spring 2015

Parkinsonia microphyllum(Foothills palo Verde)Photo taken at the ASU Tempe campus, Spring 2014

Native MesquitesPhoto of Prosopis veluntina taken at a residential backyard in North Phoenix, Spring 2012

Ferocactus cylindraceus(Compass Barrel Cactus)I did NOT take this photo- it came from Enviro Control

Elms- unspecified speciesPhoto of Ulmus parvifolia, near ASU Tempe campus, Spring 2014

Dasylirion- unspecified spe-cies (Desert Spoons)Photo of Dasylirion acrotrichum at ASU Tempe campus, Spring 2014

Oleander species(Especially Pink Oleanders)Photo of pink oleander at ASU Tempe campus, taken Spring 2014

Ruellia species(British Ruellia pictured)Photo taken at Phoenix City Hall, Spring 2015

Pennisetum setaceum ‘Rubrum’(Purple Fountain Grass)I did NOT take this photo- it came from Monrovia.com

Lantana speciesPhoto of Lantana camara ‘New Gold’, taken at the ASU Tempe campus, Spring 2014

Baccharus sarothroides(Desert Broom)Photo taken at ASU Tempe cam-pus, Spring 2014

Echinocactus grusonii(Golden Barrel Cactus) Photo taken at the ASU Tempe campus, Spring 2014

Hesperaloe species(Red Yucca varieties)Photo of Hesperaloe parviflora taken at ASU Tempe campus, 2014

Dalbergia sissoo(Indian Rosewood)Photo taken in Tempe, Spring 2014

Ebenopsis Ebano(Texas Ebony) Photo taken at the ASU Tempe campus, Spring 2014

Leucophyllum- unspecified species (Texas Sage varieties)Photo of a Leucophyllum frutescens ‘Compacta’, Phoenix, 2013

Barrel Cacti- unspecified speciesPhoto of a Ferocactus wislizeni, taken in North Phoenix, 2014

Opuntia- unspecified species(Prickly Pear species)Photo of an Opuntia macrocentra var. violacaea taken at ASU Tempe campus, Spring 2014

Plants that were noted as being both Overused and Bulletproof:• Hesperaloes- unspecified species; maintenance

tends to leave it alone, but it can get up to 6’ wide, so be sure to plant it far enough back from walkways

• Oleander species (particularly Pink Oleanders), very reliable and always blooms

• Lantana species (particularly Lantana camara ‘New Gold’)

General Notes: Texas Ebony can get very large, is slow growing, and has a wicked thorn, but can be planted anywhere and provides great shade; Palo Blanco Trees are very messy. Foothills Palo Verdes do not appreciate tight spaces.

Ash trees- unspecified speciesPhoto of a Fraxinus veluntina, tak-en at the Phoenix Historic Home-steads Park, Summer 2014

Aloes- unspecified speciesPhoto of Aloe parryi truncata, taken at the ASU Tempe campus, Spring 2014

Agave weberi(Weber Agave)Photo taken at the ASU Tempe campus, Spring 2014

Citrus aurantium(Sour Orange)Photo taken at the ASU Tempe campus, Spring 2014

Ferocactus wislizeni(Fishhook Barrel Cactus)I did NOT take this photo- it came from The American Southwest

Larrea tridentata(Creosote)Photo taken near the Veterans Way LRT station, Spring 2014

22

FAVORITE PLANTS, CONTINUED PLANTS TO AVOID- This list is opinion-based, so some of these plants might be on the list of favorites and the list of overused plants. There was no consen-

sus among interviewees about these plants; it shows the great diversity of design styles even within the (relatively small) study group.

SHADE-LOVING / INDOOR PLANTSThis plant list was provided by Shari Zimmerman during her interview.

• Agaves • Aloes • Aspidistra elatior (Cast Iron Plant)• Beaucarnea recurvate (Ponytail Palm)• Bromeliad species• Chlorophytum comosum (Spider Plant)• Dioon edule (Mexican Cycad)• Dracaena fragrans (Corn Plant)• Dracaena species• Ferns • Ficus benjamina (Weeping Fig)• Ficus elastic (Rubber Plant)• Ficus palmeri (rock fig)• Ivy • Jasminum sambac (Arabian Jasmine)• Kalanchoe species• Musa paradisiaca (Banana- though there are

hybrid varieties available)• Philodendron species• Philodendron species• Portulacaria afra (Elephant Food)• Saintpaulia (African Violets)• Sansevieria species (Mother-in-Law’s Tongue)• Schefflera species • Strelitzia species (Bird of Paradise)• Tradescantia pallida (Purple Heart, Wandering

Jew)• Zamia species• Zephyranthes species (Rain Lillies)

Hybridized Palo Verdes (thornless)They tend to fail in landscapes - overwatering causes quick top growth, so branches sanp off or tree falls over because roots aren’t encouraged to grow outward. Poor pruning raises the canopy, allowing the wind to topple the tree.

Grevillea robusta(Silk Oak)Photo taken at ASU Tempe cam-pus, Spring 2014

Phyllostachys aurea(Golden Bamboo) Photo taken in North Phoenix backyard, Spring 2015

Populus Species(Cottonwoods)Photo taken at ASU Tempe cam-pus, Spring 2014

Platanus occidentalis(Sycamore)I did NOT take this photo- it came from the Image Archive of Central TExas Plants

Hibiscus speciesPhoto of Hibiscus rosa-sinensis, taken at the ASU Tempe campus, Spring 2014

Previously Pictured Recommended Plants:• Olneya tesota (Ironwood)• Quercus virginiana (Southern Live Oak)• “Native Species” (unspecified plants)- this reflects

the general trend of professionals in the area to use plants that are desert-adapted, particularly those that are native to the Sonoran Desert

GENERAL NOTES: Weber Agaves were preferred because they looked “strong and confident”, and Sour Oranges provide a pleasant aroma. Ash trees, Southern Live Oaks, and Chinese Pistaches were good for tight spaces, while Dasylirion species were recommended because they tend to be left alone by maintenance crews (and therefore are spared the usu-al “poodling”). Firethorn bushes, also called “Pyracan-thas”, add a great splash of color, can be used as a vine, and attract birds.

Carnegiea gigantea(Saguaro) Photo taken at the Desert Botani-cal Garden, Spring 2014.

Cylindropunia species (Cholla species)Photo of a Cylindropuntia acan-thocarpa, taken at the Desert Botanical GArden, Spring 2014

Previously Pictured Plants to Avoid:• Ash trees - not even Fraxinus veluntina, the Arizo-

na Ash• Dalbergia sissoo (Indian Rosewood)- very

root-happy, particularly in grass; a little too inva-sive

• Oleander species- they are water wasters!• Opunitas (Prickly Pear Species)- avoid these in ur-

ban areas where people are likely to come in con-tact with them; they can be very thorny

General Notes: The following plant categories were placed in the “Plants to Avoid” category:• “Big Trees with Thirst Issues”• “High Water Use Plants”• “Short Lived Plants”- short-lived plants include

plants that live 1-3 years; street trees tend to last only 7-10 years because of the maintenance pro-vided (they should live 15-30 years); essentially, plants that don’t live long will end up getting re-placed by maintenance crews, who might choose another plant entirely and ruin the design intent

Acacia greggii has very wicked thorns, as do the Cholla species; the Saguaro was placed on the list because some of the interviewees did not feel they bleonged in urban areas. The Silk Oak is far too messy (and no longer in vogue), while Golden Bamboo sim-ply fries in the Phoenix sun. Verbenas were cited as undependable despite their beauty.

Acacia greggii(Catclaw Acacia)Photo taken at Boyce Thompson Arboretum, May 2015

Pistacia chinensis(Chinese Pistache)Photo taken at ASU Tempe cam-pus, Spring 2014

Pyracantha species(Firethorn)Photo taken at Taliesin West, Feb-ruary 19, 2014

Brachychiton populneus(Australian Bottle Tree)Photo taken at the ASU Tempe campus, Spring 2014

Verbena- unspecified speciesI did NOT take this photo- it is from GardenBanter.co.uk

Photo of a Parkinsonia x ‘Desert Museum’; this is a hybrid Palo Verde, but it doesn’t seem to have the same problems.

23

DISCUSSION

SURVEY – QUESTIONS, LAYOUT, AND GENERAL DESIGN The survey was generally well designed, though it did have some flaws. Questions 1-3 were well developed and received the in-tended types of answers, but this was most likely because they did not contain a free-response component as their main element. Questions 4-6 were a bit more challenging, because they were entirely free-re-sponse. Question 4 asked for good examples of planting designs in difficult places, specifically within the Phoenix/Tempe area. Most re-spondents gave great examples, but some were from places outside the study area while others were too vague to be helpful. Sites were suggested in Scottsdale and some even as far away as Buckeye; these sites were simply not visited because they were not statistically relevant to this study (though they will be considered for future studies). Sites in Scottsdale were specifically eliminated because the city seems to place a much higher value on plants there than in Phoenix or Tem-pe, and thus the plants generally face less harsh conditions. The biggest problem with the survey was tracking the respondents – the software would give me a person’s response, complete with the date and time it was started and completed and the user’s IP address, but I could not discern who the person was unless a name was entered in one of the text boxes. I wanted to avoid unnecessarily pestering professionals with reminder emails and even attempted to track the IP addresses, but none of the websites I checked offered a particularly precise location for them. Thus, I included a request for respondents to add their names to the contact box when I sent the reminder emails. I also rephrased Question 6 of the survey to clarify my intentions, but there was no way to track the first few respondents.

INTERVIEW – QUESTIONS, FORMAT, AND GENERAL DESIGN I had begun the process with the intent to record each and every interview with the video function on my camera. Unfortunately, the first day I went to conduct interviews, I didn’t remember to take the camera out. I was quite nervous for my first interview, because I had never interviewed a complete stranger before. I was a bit less nervous for the second interview, and I could ask the questions more concisely because I had a better idea of how the other person would respond. I altered the questions as my confidence grew, so that I could ask more and better questions to foment more precise results. I found that the interviewees were comfortable and amicable talking to me about plants and plant selection, and I had noticed in previous inter-views (I once interviewed a Dean of the Honors College) that even the mention of a recording seems to make people reluctant to talk.

REFLECTION | FUTURE RESEARCH I learned an immense amount about what makes urban situ-ations harsh, and even more about the widely differing viewpoints of local Landscape Architects regarding plant selection. Some chose plants that were ‘bulletproof’ purely for the sake of ensuring that the plants could stand up to current maintenance practices, while others considered the extremely hardy plants ‘overused’ and tried to avoid adding them. I also learned a bit more about the most controversial case study on the list, the Ficus Trees on Mill Avenue. Some profession-als loved them for their deep shade (which they said was appropriate to a Downtown area), and their provision of visual shade (via their deep green color). Other professionals said that the trees were a terrible idea because the species isn’t as frost hardy as they wanted for a street tree, and they attract birds that dirty up the cars parked

beneath them. I also learned that the trees are actually illegal for right-of-ways (they aren’t low water use), so the City simply zoned the area as a park to get around the regulation. I also discovered several topics that require further research, beyond the scope of this project. Maintenance, for example, was men-tioned by every professional I interviewed, and it was always linked to a complaint about how current maintenance practices are harming the plants’ health and destroying the design intent of a given site. Thus, an investigation into the relationship between Landscape Archi-tecture and Maintenance is warranted. There seems to be a break-down in communication between the two professions, and it must be fixed. The reviewers at my thesis defense suggested gathering the landscape architects and maintenance crews together to discuss each party’s concerns about the other’s behavior, and pushing landscape architects to include maintenance manuals with their designs.

24

BIBLIOGRAPHY

• “Hesperaloe x Pink Parade,” Mountain States Wholesale Nursery, http://www.mswn.com/plants/database/plant/hesper-aloe-x-pink-parade-pp-21828/ (accessed May 2015). This source was used to determine the full Latin name of the Pink Parade Hesperaloe.

• “Salt Tolerant Plants.” http://www.mswn.com/media/salt_tolerant_plants.pdf (accessed June 22, 2014).• Arizona Cooperative Extension, “Soils and Fertilizers: Soils: Caliche.”• Arizona Cooperative Extension. “Soils and Fertilizers: Soils: Caliche.” https://ag.arizona.edu/pubs/garden/mg/soils/caliche.

html (accessed April 11, 2015).• Arizona Department of Water Resources. “Low Water Use/Drought Tolerant Plant List.” http://www.azwater.gov/azdwr/

WaterManagement/AMAs/documents/LWU_Plants1.pdf (accessed June 25, 2014).• City of Scottsdale. Design Standards & Policies Manual, Chapter 2, Section 2-1, pg 20. http://www.scottsdaleaz.gov/

Assets/Public+Website/design/dspm/2009/CH-02RECORD.pdf (accessed May 2015). This source was used for its list on acceptable native plants for detention basins and drainage channels; the exact page is included in the Appendix section of this document.

• Duffield, Mary Rose, and Warren D. Jones. Plants for Dry Climates: How to Select, Grow, and Enjoy. Cambridge, MA: Perseus Publishing, 2001. This was another great source for plant identification and gathering information about what each plant needs to thrive.

• Jones, Warren D. and Charles M. Sacamano. Landscape Plants for Dry Regions. Cambridge, MA: Fisher Books, 2000. This source was extremely helpful for plant identification and verification of plant ‘cultural requirements’.

• Mathura, Kirti. The Arizona Low Desert Flower Garden: A Seasonal Guide to Bloom, Height, Color, and Texture. Layton, UT: Gibbs Smith, 2007. This source was used to as a reference for some of the flowering plants.

• Mielke, Judy. Native Plants for Southwest Landscapes. Austin, TX: University of Texas Press, 1993. This was an excellent source for plant identification and contained notes about the “landscape use” of each plant; this information was helpful for learning about where to place each plant in the overall scheme of a design.

• Paul Coseo, Lecture on Green Roofs (Guest lecture in a course about Landscape Construction at ASU, Tempe, AZ, April 7th, 2015).

• Shuler, Carol. Low Water-Use Plants for California and the Southwest. Tucson, AZ: Fisher Books, 1993. • Sterman, Nan, Mary Irish, Judith Phillips, and Joe Lamp’l. Water-wise Plants for the Southwest. Brentwood, TN: Cool

Springs Press, 2010.

IMAGE SOURCESThe following sources were used to obtain images of plants in the research findings section (where there are notes beside the photos I did NOT take). Google Maps were used to create the annotated aerial images and context maps in the Case Study pages.

• Dogs N Petunias (this is a username), Katie Ruellia Growing In My Yard in 2008, 2008, DavesGarden.com, http://davesgarden.com/guides/pf/showimage/246682/#b (accessed May 2015). This source was used for an image of Ruellia brittoniana ‘Katie’, Katie Ruellia.

• Doreen Wynja, [untitled image of Brakelights Red Yucca], unknown date, Monrovia: Horticultural Craftsmen Since 1926, http://www.monrovia.com/plant-catalog/plants/3198/brakelights-red-yucca/ (accessed May 2015). This source was used for an image of Hesperaloe parviflora ‘Perpa’, Brakelights Red Yucca.

• Doreen Wynja, [untitled image of Little Ollie Dwarf Olive], unknown date, Monrovia: Horticultural Craftsmen Since 1926, http://www.monrovia.com/plant-catalog/plants/1894/little-ollie-dwarf-olive/ (accessed May 2015). This source was used for an image of Olea europaea ‘Montra’, Little Ollie Dwarf Olive.

• Doreen Wynja, [untitled photo of Purple Fountain Grass], unknown date, Monrovia: Horticultural Craftsmen Since 1926, http://www.monrovia.com/plant-catalog/plants/1935/purple-fountain-grass/ (accessed May 2015). This source was used for an image of Pennisetum setaceum ‘Rubrum’, Purple Fountain Grass.

• Ericameria laricifolia, October 11, 2008, Sonoran Desert Naturalist, http://www.arizonensis.org/sonoran/fieldguide/plan-

tae/ericameria_laricifolia.html (accessed May 2015). This source was used for a photo of Ericameria laricifolia, Turpentine Bush.

• Holly (Ilex), October 7, 2011, Florafinder.com, http://www.florafinder.com/Species/Ilex.php (accessed May 2015). This source was used for an image of an Ilex (Holly) plant.

• Iain Harrison, Senna artemisioides, http://images.swinburne.edu.au/handle/1111.1/2910 (accessed May 2015). This source was used for an image of Senna artemisioides, Feathery Senna.

• Janet Hall, Star Jasmine Vine, unknown date, Gardenista.com, http://www.gardenista.com/posts/alternatives-to-ivy-verti-cal-growers (accessed May 2015). This source was used for an image of a Star Jasmine plant.

• Kathy Woodward, [untitled image of Lavender plant], May 29, 2013, The Garden Glove, http://www.thegardenglove.com/grow-lavender-like-the-french-7-easy-tips-for-anyone/ (accessed May 2015). This source was used for an image of Lavender.

• Laura Murphy, [untitled image of Blue Hibiscus bush], unknown date, Arizona Cooperative Extension (Mojave County Division), http://cals.arizona.edu/mohave/master_gardeners/kingman/articles/bluehibiscus.pdf (accessed May 2015). This source was used for a photo of Alygoyne huegelii, Blue Hibiscus; it is the second picture in the document.

• Leaf Underside, unknown date, Image Archive of Central Texas Plants, http://www.sbs.utexas.edu/bio406d/images/pics/plt/platanus_occidentalis.htm (accessed May 2015). This source was used for an image of a Platanus occidentalis leaf (com-mon name- Sycamore).

• Mountain States Wholesale Nursery, Pink Parade Hesperaloe, The Greenery: Nursery and Garden Shop, http://www.greenerynsy.com/california-friendly/ (accessed May 2015). This source was used for an image of Hesperaloe x Pink Parade, Pink Parade Hesperaloe.

• Pots of the Green and Yellow Variegated Sanseveria, unknown date, OnlinePlantGuide.com, http://www.onlineplant-guide.com/Plant-Details/2441/ (accessed May 2015). This source was used for an image of Sanseveria trifasciata ‘Gold Extreme’, Gold Extreme Sanseveria.

• Snow Cap, unknown date, Cross Creek Nursery, http://www.crosscreeknursery.com/indian-hawthorn.html (accessed May 2015). This source was used for an image of a Snow Cap Indian Hawthorn plant.

• Southern Nevada Water Authority, http://www.snwa.com/apps/plant/detail.cfml?type=84&id=14767 (accessed May 2015). This source was used for a photo of Calliandra californica (Baja or Red Fairy Duster).

• Trixis californica, Arizona-Sonora Desert Museum, April 19, 2008, Xeriscape Landscaping Plants for the Arizona Desert Environment, http://www.delange.org/Trixis/Trixis.htm (accessed May 2015). This source was used for an image of Trixis californica, American Threefold.

• Untitled image of a white Verbena flower, unknown date, GardenBanter.co.uk, http://www.gardenbanter.co.uk/gar-den-photos/203236-white-verbena.html (accessed May 2015). This source was used for a photo of an unidentified Verbena plant.

• Untitled image of Ferocactus cylindraceus, unknown date, Enviro Control: Pest and Horticultural Solutions, http://www.envirocontrol-llc.com/wp-content/uploads/Compass-Barrel-Ferocactus-cylindraceus-red-2.jpg (accessed May 2015). This source was used for an image of Ferocactus cylindraceus, Compass Barrel Cactus.

• Untitled Image of Muhlenbergia rigens, unknown date, San Marcos Growers, http://www.smgrowers.com/products/plants/plantdisplay.asp?plant_id=729 (accessed May 2015). This source was used for a picture of Muhlenbergia rigens, Deer Grass.

• Vinca major ‘Variegata’, unknown date, Plantify.co.uk, https://www.plantify.co.uk/Vinca-major-Variegata/plant-7776 (accessed May 2015). This source was used for a photo of a Vinca major ‘Variegata’, common name: Greater periwinkle Variegata.

• Yellow Fruit of Ferocactus wislizeni, the Arizona Barrel Cactus, unknown date, The American Southwest, http://www.americansouthwest.net/arizona/catalina/ferocactus-wislizeni_l.html (accessed May 2015). This source was used for a photo of Ferocactus wislizeni, Fishhook Barrel Cactus.

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Case Study: City Hall

Plant ListTrees

Palo Brea (Parkinsonia praecox)Honey Mesquite (Prosopis glandulosa)Cascalote Tree (Tara cacalaco)

Shrubs/ AccentsBeaked Yucca (Yucca rostrata)No common name (Agave vivipara var. vivipara)Red Yucca (Hesperaloe parviflora)Regal Mist (Muhlenbergia capillaris Regal Mist)Lantana- Red and Orange (‘Lucious Citrus Blend’ Lantana)Katie’s Ruellia (Ruellia brittoniana)Desert Ruellia (Ruellia peninsularis)Chuparosa (Justicia spicigera)Evening Primrose (Oenothera primavera)Deer Grass (Muhlenbergia rigens)

Grass/ GroundcoverMost likely Bermuda (small lawns)

This is the base of a Honey Mesquite; it sits in a lawn with a sprinkler which seems to hit it - this may be the cause of the discoloration near the base of the trunk

Plantings beside the fountain help soften the architecture and seem to be doing very well in the full sun; maintenance does tend to trim them rather harshly into balls

Another raised seating planter; the spikiness (even if it is only visual) of the understory plantings may prevent some people from sit-ting here

View facing south from the building’s north-west corner; Ruellias are used as hedges in the wide planting zone. They are occasionally inter-rupted by single Justicia spicigera plants

The planting zone is also home to a va-riety of meters and pumps

A series of round, raised seating planters sits along the building’s southwest face; each one typically has a Palo Blanco in the center, with various levels of understory plantings

Key Features Raised Planters feature desert plants and may double as seating areas Memorial Garden with glass blocks engraved with the names of deceased city workers; slightly sunken Water Feature drowns out background noise and stone blocks under nearby trees pro-vide the ideal lunch spot

What makes this site Harsh? This site is extremely urban- it is in the urban core, nestled amongst multistory build-ings and asphalt streets. Paving on the site is also abundant, and maintenance is moderately stringent. The southern exposure is partly shad-ed by an adjacent building, but the shape of the building to the west (Phoenix Municpal Courts) leaves the western side completely exposed.

Planting Details

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Building systems take priority over plantings

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Left: Harshly pruned Ruellia, Right: soil filled concrete pots with no plants in them

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The Cascalote trees were in full bloom, and were quite healthy looking; this one sits east of the memorial garden

The grass near them memorial garden is healthy, but if a bit trampled near the corners. The sprinklers’ effects can be seen on the wall of the garden as a bit of discoloration. The ramp also has a bit of discoloration, but that may be from the sap of the tree above

This white-flowered tree sits next to the edge of a bench/wall meant to frame the memorial fountain

Dead weeds can be seen in the decom-posed granite, and the agave in the back-ground has recently bloomed

View facing south from the center of the park; the plants are doing well (the mangy Justicia is behind the Lantana)

Found just in front of the middle of the building’s southeast face, the Deer Grass and Ruellia shurbs are trimmed up into loose balls. They are seen here recovering, but there is evidence of harsh pruning. All photos taken around noon on March 12, 2015.

Small grasses planted near the rim of the planter are a bit too small to make a visual impact, but they look healthy

This unidentified aloe has some dead leaves near the bottom, and some of the tips have been cut off

Facing northwest toward the building’s southeastern edge from beside the memorial garden; trees seem to be in good health, as do the shrubs (with the exception of the ones that keep getting trimmed into balls by maintenance crews)

The grass has been shorn quite severely, but is only an issue if it is done on a regu-lar basis (rather than the yearly cut-back)

This planter has healthy plants, though one of the tree’s smaller trunks has a lot of scarring on it (sunscald perhaps)

This planter features only a Palo Verde and a lone Yucca; the tree canopy has been mostly left to its own devices

This Agava vivipara var. vivipara was found in one of the round raised planters, and is quite healthy

The flowers of the Evening Primrose are delightful, and the plants seem healthy, if a bit small for their planter

A group of Evening Primrose planted near the southwest corner of the site; they are much smaller than the shrubs

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Case Study: Phoenix Municipal Courthouse

Plant ListTrees

Palo Brea (Parkinsonia praecox)Black Mesquite (Prosopis nigra)

Shrubs/ AccentsAngelita Daisy (Tetraneuris acaulis)Blue Sotol (Dasylirion berlandieri)Regal Mist (Muhlenbergia capillaris Regal Mist)Mexican Grass Tree (Dasylirion quadrangulatum)Chuparosa (Justicia spicigera)Texas Sage (Leucophyllum frutescens)Deer Grass (Muhlenbergia rigens)

Grass/ GroundcoverOnly decomposed granite; large expanse of it beneath the Mesquite bosque

All photos taken around noon on March 12, 2015 (exept the aerial to the right, which is from Google Maps).

View from the central entry space, facing northeast toward the northeastern corner of the building; the Mesquite bosque continues to shade the path ahead

View facing east, from just inside the western edge of the Mesquite bosque; the trees have not yet begun to leaf out in earnest yet (site was visited on March 12th, 2015)

View from the southwest corner of the build-ing, facing along its angled edge toward the central entry point; pavement is both colorful and patterned

View facing the northwest corner of the lot; there is a planter that fills the space between the sidewalk and the ramp up to the door on the north side of the building

View down the side-walk beside the street, facing south

View of the northwest corner of the lot from across the street and approximately 100 feet south; a planting zone with Palo Brea trees separates the sidewalk from the street

Key Features Mesquite Bosque- this is the most distinctive element of the space, and it provides a delightful filtered shade that visitors can sit under and walk through North Side Plantings- a variety of plants with rosette-like forms visually softens the archi-tecture and makes the space pedestrian-scaled

What makes this site Harsh? This site is fairly urban; it is in the highly developed area of Downtown Phoenix, but the large mesquite bosque softens the space con-siderably, as there is very little paving within it. The shape and height of the building create a lot of shade on the northern side of the lot, in addition to creating a large amount of reflected heat.

Planting Details

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Plants are put directly beside the building in some cases

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Left: Stray irrigation tube in the mesquite area Right: Mechanical systems in the planting area

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This Regal Mist (an educated guess) has not been pruned yet, and the tan is nor-mal for the previous year’s foliage.

Some parts of the landscape have odd white patches on the soil; my best guess is that this is residue from salt in the irrigation water, left behind when the water evaporated. Alternatively, it may be white mold caused by excessive watering and poor drainage.

Close-up of the grasses and Daisies, show-ing a drainage grate that is slowly being covered by the surrounding aggregate.

View of planter north of the curving ramp; the grasses are brown and droopy, while the Angelita Daisies are relatively healthy.

View of the planting space west of the curving ramp; Angelita Daisies share the space with Texas Sages. Both are healthy.

View of the Mesquite bosqu; there once were plantings here (as I was told in the inter-views, and evidenced by the loose irrigation tubes), but they have all been removed. The limbs that hung over the sidewalk were pruned off, and sap residue has stained it.

Identification of the Mesquites was based on the texture of the bark and the number of leaves on the pinna.

This Dasylirion appears to be healthy, and can be found near point 8; it has unusual, curly fibers near the leaf bases.

This is the northeastern corner of the building; plantings tend to have grasslike forms that soften the space. Plants are clumped near the building (possibly for security reasons, as they are thorny), but become more sparse toward the sidewalk.

A volunteer Palm Tree (probably a Wash-ingtonia) sits in the raised planter at point 8- its presence may be unintentional.

Close-up of the same grass; specimens are planted approximately 2 feet apart and look very healthy.

Double rows of Deer Grass (an educated guess) line the raised planter at point 8; the grass may hide the machinery later on

Dasylirion wheeleri are planted beside the building; all appear mostly healthy, but this one has some necrosis on the leaf tips

A volunteer Palo Verde (most likely a Palo Brea, like the nearby trees) springs up in the somewhat sparse planter near point 1.

This Justicia spicegera is planted near point 1, and looks rangy and etiolated; it’s the only specimen of its kind there.

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Case Study: CityScape Courtyard

Plant ListTrees

Desert Museum (Parkinsonia x ‘Desert Museum’)Chinese Pistache (Pistachia chinensis)Live Oak (Quercus virginiana)Texas Mountain Laurel (Dermataphyllum secundiflorum)Jacaranda (Jacaranda mimosifolia)

Shrubs/ AccentsYellow Dot/ Wedelia (Sphagneticola trilobata)Dwarf Bottlebrush (Callistemon viminalis Little John)Yellow Bells (Tecoma stans)Lantana- Red and Orange (‘Lucious Citrus Blend’ Lantana)Lantana- Purple (Lantana montevidensis)Natal Plum (Carissa macrocarpa)Cast Iron Plant (Aspidistra elatior)Petunias- Red, White, and Pink

Grass/ GroundcoverMost likely Bermuda (raised planter near fountain)

View along the upper deck of the eastern edge of the court-yard, facing west.

Sculpture at street level on the eastern edge; draws visitors in for a closer look.

Small cafe in the eastern part of the plaza; its presence splits the space so that pedestrians flow around it. Beside it lies a small outdoor dining area, demarcated by raised planters.

View from the top of the stairs on the eastern part of the courtyard near the center, facing west across Central. Traffic is calm; the space is clearly the realm of the pedestrian.

View from the raised deck down onto the western portion of the courtyard. An at-grade fountain encourages children to play, and shaded seating allows ample supervision.

The raised deck provides seating and shop entrances while crossing Central Ave.

View of the stairs leading up to the eastern part of the space, facing southeast. Central Ave can be closed off for events (such as City Skate); the stairs double as seating space.

Key Features Art Pieces at each end to draw people into the space Multiple grade changes to provide visual and experien-tial interest; stairs function as seating & social space as well At-grade fountain to promote outdoor play & pro-vide evaporative cooling Mixed-use buildings offer shopping, dining, living, recreation, and work all in one space; bars and restaurants help keep the space activated and in use at nearly all times Walkable surroundings encourage increased use

What makes this site Harsh? This site is in a heavily developed area, surrounded by multi-story buildings. Paved surfaces abound (typically concrete); reflected heat can be intense, though the taller buildings can help shade parts of the space during the day. Irrigation is unlikely to be a problem, but maintenence may be strict (and potentially harm the plants with improper pruning).

Planting Details- Microclimates and Surfaces

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Multi-level concrete planters offer a wider variety of microclimates + visual interest

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The raised lawn provides the trees with extra water and soil depth as they the shade people

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View looking down the stepped planter on the south part of the middle court-yard, looking toward Central Ave

Same planter, viewed looking up toward the courtyard; the deep green of the plants helps emphasize the shade. The tall building behind this planter blocks the sun for a good portion of the afternoon, yet the Lantana and Yellow Dot still thrive.

This lantana is on one of the stepped planters; it receives a lot of shade be-cause it’s between the tall buildings

Tecoma stans trimmed into a hedge on the eastern portion of the site; receives east and west sun, but mostly in shade

An oak tree seems compressed beneath the shade structure in the middle of the courtyard, on the east side of Central

A delightful stepped planter on the site’s eastern edge entices visitors to climb the stairs; the plants include petunias near the street, a Chinese Pistache, some Yellow Bells, Yellow Dot, and Purple Lantana; photos taken slightly after noon on March 25, 2015.

Desert Museums sit in the north side of the planter on the eastern side of the site; they get east and west sun

Aspidistra elatior in the red and white petunias in the stepped planter on the north side of the courtyard near Central

These trees are actually sitting atop a parking structure, and receive sun for most of the day. Though they may receive heat from the structure beneath them, they do not face as much reflected heat from the buildings.

The deep shade provided by the buildings covers the eastern half of the space, pro-viding a pedestrian refuge from the sun

Yellow Bells sit beside the steps; the foli-age looks delightfully soft and the plant looks quite healthy

These plants sit at the top of the stairs on the east edge of the site, and they receive mostly east and west sunlight

A Desert Museum sits amidst a sea of Yel-low Dot and Yellow Bells, but the trunk is oddly brown for a tree of that age

Tecoma stans in bloom; used as a privacy screen for a dining area in the middle of the courtyard on the

View of the lower portion of the same planter; the Chinese Pistache is just be-ginning to leaf out again

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Case Study: Cancer Survivor’s Park

Spiral concrete sculptures act as a gateway at the south end, announcing the park’s presence to the street - they sit behind the sculpture and match the ones on the north end

The central sculpture provides seating and may double as a water feature, but it is current-ly dry and has some trash in it (most likely the result of wind carrying light items into it)

The meandering con-crete path, lined with desert trees, receives filtered shade

A small ramada with a glass peak (which lets light in) houses a drinking fountain and a sign informing visitors of the park rules; it does not appear to be popular, as it lacks seating

Key Features Sculptures at each end anchor and help define the space; the central sculpture was made by local artists and includes a water feature A shaded, curvilinear path draws visitors through while creating a pleas-ant microclimate Bronze signs give visitors hope and information about cancer and the steps to surviving it

What makes this site Harsh? Located in a fully developed urban area, this miniature park sits in a meandering medi-an between two streets. Neither street draws heavy traffic, though it is paved (and thus re-flects heat). The park faces 2 parking lots to the west, and several 1-3 story buildings to the east. Reflected heat and lackluster maintenance are the main challenges for this space.

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Above: Entry statue (depicting cancer pa-tients’ journey through treatment) at Mc-Dowell Road. Below: View of the statue from further down the path. Right: Close-up view of the central sculpture

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Planting Details

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Above: lush desert plantings lend visual interest and textureLeft: striking cactus increase ap-preciation for desert plantsBottom: faux ravine lined with stones brings to mind the natural drainage features while serving to manage stormwater1

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The sculpture on Wiletta Street is ab-stract and made of chunky steel

TreesSaguaro (Carnegiea gigantea)Desert Museum (Parkinsonia x ‘Desert Museum’)Ironwood (Olneya tesota)

Shrubs/ AccentsArgentine Giant (Echinopsis candicans)Golden Barrel Cactus (Echinopsis grusonii)Pedalanthus (Euphorbia lomelii)Little-Leaf Cordia (Cordia parvifolia)Red Yucca (Hesperaloe parviflora)Texas Sage (Leucophyllum frutescens ‘Compacta’)Lantana- Yellow (‘Pot of Gold’ Lantana)Lantana- Red and Orange (‘Lucious Citrus Blend’ Lantana)Murphey’s Agave (Asparagus densiflorus Meyersii)Ocotillo (Fouquieria splendens)

Grass/ GroundcoverNone- only decomposed granite

Plant List

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Nonetheless, it should be noted that the plants are allowed to attain their natural forms

The swale loosely lined with river rock matches the curvilinear qualities of the path, though it is curious that the bottom of the swale does not have river rocks. Nonetheless, the plants are healthy and for the most part planted far enough away from the road

Facing north toward the pavilion at the lower end of the park, more dead weeds can be seen in the planting area

Dead weeds can be seen in the decom-posed granite, and the agave in the back-ground has recently bloomed

View facing south from the center of the park; the plants are doing well (the mangy Justicia is behind the Lantana)

Just slightly south of the center of the park, the Argentine Giants are doing well; they receive filtered light all day from the combination of Palo Verdes and Ironwoods, which help shelter the cacti from full sun; photos taken around 4-5 pm on March 12, 2015

This saguaro appears to have had some sort of accident... the scars are on the por-tion of the plant that faces west

Most of the plants appear to be healthy, though the Justicia beside the Argentine Giant seems a bit rangy

The cacti here seem to be a little mangy, and a volunteer palm tree has sprung up near the base of the Ironwood. The plants closer to the street seem to be struggling or dead; this scene is just south of the center of the park, on the western edge of the street

This cactus has had its top lopped off, but it too has kept growing. Cigarette butts litter the ground near the curb

This Argentine Giant is heavily damaged, yet quite determined to keep growing; it is near the north end of the site

These cacti are clumped near the road on the eastern side of the park, and don’t seem to be bothered by the pavement

This agave presents a healthy form, though some of the lower leaves are part-ly brown

Some agave pups have sprung up, but they don’t seem to be doing very well- the tips are brown and some are dead

Argentine Giants seem to be a large part of this design, though some of them seem to have the slightest bit of sunscald

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Case Study: Phoenix Art Museum

Jojoba shrubs pruned into blobs line this reten-tion basin; the foliage on the Mesquite trees is also very sparse. The aloes against the building (south facing) are doing very well

This covered space leads up to the entrance; planters of cacti and Pedalanthus line the sides, and the streetscape of Palo Breas and Yuccas continues northward uninterrupted

The large sculpture is surrounded by Jo-joba bushes pruned into 2’x3’ balls

The southwest corner of Alvaredo Road and Coronado Road has a large red sculpture and yuccas, grasses, cacti, and a few trees... though many of the plants are pruned harshly

Key Features Sculptures throughout the space serve as focal points and attention-grab-bers to draw visitors in (ie: red dinosaur) Widely varied plantings keep the visitor interested in the plantings Interactive spaces allow visitors to sit on the grass (entry space) Interior courtyard (not photo-graphed; inaccessible to public) - space used for exhibits and events of all types

What makes this site Harsh? The site is in an urban area, and as such faces the usual urban heat island effect, com-bined with the large amount of reflected heat from the parking lot and paved surfaces. Sur-prisingly, maintenance also seems to make the site harsh for plants. Many shrubs are unneces-sarily trimmed up into balls or trashcan shapes, which harms the plant and looks awful.

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Planting Details

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Above: harshly pruned yuccas sit beside the parking lot Left: a purple petunia sits in a raised bed on the east side of the southern buildingBottom: Jojobas pruned into tiny balls in the parking lot medians beside Coronado Road1

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Mesquites rise up from within a hedge of Texas Sage (south side streetscape)

TreesCascalote Tree (Tara cacalaco)

Palo Brea (Parkinsonia praecox)

California Fan Palm (Washingtonia filifera)

Texas Ebony (Ebenopsis ebano)Mesquites (species uncertain)

Shrubs/ AccentsCandelilla

(Euphorbia antisyphilitica)Pedalanthus

(Euphorbia lomelii)Red Yucca

(Hesperaloe parviflora)Compact Texas Ranger (Leuco-phyllum frutescens ‘Compacta’)

Murphey’s Agave (Agave murpheyii)

Fox Tail Agave (Agave attenuata)

Twin Flowered Agave (Agave geminiflora)

Organ Pipe Cactus (Stenocereus thurberi)

Totem Pole Cactus (Lophocereus Schottii forma

monstrosus)Dagger Plant (Yucca aloifolia)

Mountain Yucca (Yucca schottii)Golden Barrel Cactus

(Echinocactus grusonii)Jojoba

(Simmondsia chinensis)Aloe Vera (Aloe vera)

Mexican Petunia (Ruellia brittoniana)

Deer Grass (Muhlenbergia rigens)

Bear Grass (Nolina microcarpa)Rosemary

(Rosmarinus officinalis)Annuals (petunias,

Bougainvillea (a pink variety)

Grass/ GroundcoverMost likely Bermuda

Plant List

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This Texas Ebony is doing well, but the al-oes beneat it have had their lower leaves unnecessarily cut off

This raised planter filled with Rosemary and mixed flowers was found near the eastern edge of the southern building, beside an entrance. The flowers are doing well, though they aren’t desert natives- these are most likely replanted annually at least

These cacti receive morning sun, and seem to be rather leggy, though they do appear to be doing well

These Golden Barrels receive noon and af-ternoon sun, and seem to be doing well (though they are twisting a bit)

This Pedalanthus sits beside the building just beyound the roof; it gets afternoon sun and is quite happy

The museum has a raised planter of Candelilla attached to its west side, where they seem to be doing well. Palo Breas are trimmed up rather harshly and planted under small tree grates and provide little shade; photos taken around 5 pm on March 12, 2015

The palm trees and associated planters of Texas Sage are part of a larger streets-cape, and take the reflected heat well

The small courtyard space near the group entrance on the west side; plants are do-ing well, despite maintenance practices

The Pedalanthus and Totem Pole Cactus make a striking display in this planter; however, the Pedalanthus in the shade (right side) seems to be smaller and less happy than the plants that get more sun (left side in photo) - all receive western sun in the afternoon

This Compact Texas Ranger has been planted too close to the walkway and trimmed into a pointlessly narrow hedge

This cactus is doing well, and can be found at the southwest corner of Coronado Road and Alvarado Road

Yet another example of harsh pruning, this Deer Grass is beginning to recover from being sheared into balls

The Ruellias in the parking lot are not as healthy as they could be; this could be a result of pruning or reflected heat

Mesquites are used as parking lot trees, but they are not providing very much shade; Ruellias below are pruned harshly

Another set of Jojobas pruned into tiny, individual balls... These plants get far too big to be planted in these narrow spaces

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Case Study: Arizona Center

The space created between the buildings was almost entirely paved; the cental area had an unshaded water feature with sandstone blocks for seating.

View facing southeast across lawn; it is being set up for an event and is ringed by tall and healthy Date Palms, a signature plant through-out the entire site.

Key Features Date Palms throughout the space unify it and give the pedestrian a sense of enclosure, grandeur, and a bit of shade

Central Open Space allows visitors a shady place to sit & can be rented out

Multiple Levels give pedestrians more options; though the top houses of-

fic space instead of the food court Unique Shade Structures provide

spatial unity, shade and visual interest

What makes this site Harsh? Arizona Center is a development in Down-town Phoenix, and a large portion of the site is taken up by buildings. A multistory parking ga-rage generates reflected heat for the plants be-side it, and the tall buildings case a good deal of shade on the open spaces throughout the day. Additionally, it is a mall- open spaces are mostly pavement (except for the large lawn).

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Above: View from parking garage south-east across lawn. Below: View of the cen-tral courtyard, facing southwest. Right: View (facing south) along perimeter of central courtyard

The streetscape along the southern edge was quite pleas-ant to walk along.

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View facing north into the central courtyard, shaded by skyscraper; the space was rented on the day of the site visit (April 30, 2015), so no photos were taken from inside the space.

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Planting Details

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Above: small shrubs planted on the borders of the northern lawnLeft: an Agave desmettiana along the southern streetscape Bottom: Unidentified grass-like shrub in a raised planter near point 6; it has large pods and white trumpet-like flowers1

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Mesquites rise up from within a hedge of Texas Sage (south side streetscape)

TreesIndian Laurel

(Ficus microcarpa var. Nitida)Mediterranean Fan Palm

(Chamaerops humilis)Date Palm (Phoenix dactylifera)Mesquites (species uncertain)

Jacaranda(Jacaranda mimosifolia)

Shrubs/ AccentsSmooth Agave

(Agave desmettiana)Pedalanthus (Euphorbia lomelii)

Red Yucca (Hesperaloe parviflora)

Compact Texas Ranger (Leuco-phyllum frutescens ‘Compacta’)

Wandering Jew/Purple Heart (Tradescantia pallida)

Giant Hesperaloe (Hesperaloe funifera)

Blue Elf Aloe(Aloe x ‘Blue Elf’)

Octopus Agave (Agave vilmoriniana)

Coral Fountain(Russelia equisetiformis)

Boxwood(Buxus sempervirens)

No Common Name(Agave americana subsp. ameri-

cana ‘Medio Picta’)Tropical Hibiscus

(Hibiscus rosa-sinensis)Natal Plum

(Carissa macrocarpa)Rosemary

(Rosmarinus officinalis)African Iris/Morea Iris

(Dietes iridioides)Confederate Jasmine

(Trachelospermum jasminoides)Sago Palm (Cycas revoluta)

Grass/ GroundcoverMost likely Bermuda

(in lawn areas)

Plant List

Notes About the Site The site boundaries are shown with the dashed red lines above; only the bottom portion was photographed. The top portion only contained a small amount of streetscape plantings, and the rest of the space was taken up by buildings or the at-grade parking lot. The northern edge did not really offer a pedestrian-friendly entrance point or points. This development is not considered a smashing suc-cess, as most of the original shops are gone and and it is currently half-empty. Critics blame the failure on Phoenix’s suburban lifestyle and the lack of high-end residential spaces nearby to feed the mall.

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Facing west from beside the western edge of Arizona Center 1, the Hesperaloes appear to be doing very well

These Octopus Agave are planted beside the base of Arizona Center 1- and they appear to be suffering greatly for it. They are generally etiolated and are leaning toward the sun, but the building’s shade is smothering them.

These Octopus Agaves are doing very well in the southwestern corner of the planted areas of the central courtyard

Agaves, Purple Heart, Giant Hesperaloe, and Coral Fountain are thriving in the fil-tered shade of the Date Palms at Point 6

The Rosemary beside the street seems to be suffering from the reflected heat of the pavement, and is a little rangy

View from the second level, looking northeast across the lawn with the palms; the shrubs seem healthy and the grass is well maintained. The shade is from the building in the right side of the photo. All photos were taken around noon on April 30, 2015.

The Ficus trees are thriving, and provide hearty shade over the small space; they also serve as an entry for the courtyard

Jasmine vines twine around the columns of the shaded walkway; they are rather small, but they may be newly planted

This is the planter on the east side of Arizona Center 1 (the tall building furthest south on the site). The Agaves, Aloes, Pedalanthus, and Purple Heart plants are all very happy and the mix provides an excellent source of visual interest

This Hibiscus is also on the second level, but it gets mainly eastern sunlight and partial shade

An unidentified potted plant blooms hap-pily under the shade provided by the can-vas sails on the second level of the mall

This potted Hibiscus is at Point 7, and has unhealthy yellow leaves; this spot gets full sun all day

The portion that is in the sun, however, is thriving and looks full and healthy

This Boxwood appears to be unhappy in the shade and is pruned to fit the oddly narrow planting space

An unidentified grass appears to be a bit lackluster- it is planted in the hot, paved area between the buildings

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38Case Study: Mill Avenue

The west side of the street has much more con-tinuous shade; though in some spots the tree grates look a bit too small for the trees that grow in them

The plantings in the street median are more desert-adapted than the sidewalk plantings, and the low vehicular speed reduces the chanc-es of damage to the plants (via wind, etc.)

A small loading area on the east side of 6th street; very few plantings there

Chinese Elms help shade the street, but with-out the presence of tall buildings and Ficus on the east side of the street at this point, the pe-destrians are left unshaded

Key Features Ficus Trees unify the space and provide dense shade for the sidewalks Varied Storefronts provide visual interest and a pleasant shopping expe-rience; wide sidwalks allow the space to become a promenade if needed Small Courtyards right off the main space provide more visual interest and the chance to explore; they also tend to have more intricate plantings

What makes this site Harsh? Located in a fully developed urban area, this miniature park sits in a meandering medi-an between two streets. Neither street draws heavy traffic, though it is paved (and thus re-flects heat). The park faces 2 parking lots to the west, and several 1-3 story buildings to the east. Reflected heat and lackluster maintenance are the main challenges for this space.

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Above: Streetscape on the east side of the street, approaching the mill. Below: View Hayden Station (might be Hayded Square). Right: Crosswalk at 4th Street; narrow lanes reduce vehicular speed.

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Planting DetailsLeft: Ficus microcarpa var. nitida (Indian Laurel) trees line the streets and provide deep shade of the side-walks. Below: Annuals share planters with some of the trees. Bottom: A tree grate filled with sand prevents trash from accumulating, but provides no frost bene-fit.

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The Ficus trees con-tinue nearly up to the intersections, which are very wide.

TreesIndian Laurel

(Ficus microcarpa var. nitida)Chinese Elm

(Ulmus parvifolia)Date Palm

(Phoenix dactylifera)Pygmy Date Palm (Phoenix roebelenii)

Arizona Ash (Fraxinus veluntina)

Unidentified potted tree- white flowers

Shrubs/ AccentsFox Tail Agave

(Agave attenuata)Fox Tail Fern (Asparagus

densiflorus ‘Meyersii’)Smooth Agave

(Agave desmettiana)

Bear Grass (Nolina microcarpa)Fountain Grass

(Pennisetum setaceum)Red Yucca

(Hesperaloe parviflora)Lantana- Yellow

(‘Pot of Gold’ Lantana)Pink Oleander (Nerium ole-

ander, pink cultivar)Coral Fountain

(Russellia equisitiformis)Mexican Bird of Paradise

(Caesalpinia pulcherrima)Annuals (Geraniums, Bego-

nias, Verbenas, etc.)

Grass/ GroundcoverNone- only paving

Plant List

3rd Street

5th Street

6th Street

7th Street

University Drive

4th Street

Mill

Ave

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An at-grade planter with healthy Pygmy Date Palms and Red Yuccas. Photo taken April 16 near 5pm, west side of Mill Ave.

One of the many small courtyards jutting off the main avenue features this small rock waterfall. It lends a calming sound to the air and tempts the pedestrian with the promise of a more tropical milieu within; photographed April 16 near 5pm, north of 5th Street

Close-up of some of the desert-adapt-ed understory plantings; most appear healthy. Photographed April 16 near 5pm

The median plantings are very happy; they don’t suffer from pedestrain trampling. Photographed March 16 around 12pm

View of a ficus tree sharing a planter with annuals; the fence is meant to keep trash out. Photo taken March 16 around 12pm

This is a view into “Hayden Station”; it has Southern Live Oaks in small planters, and fur-ther down the corridor are Hibiscus trained into trees in raised planters. This area gets morning and early afternoon sun; the photo was taken on April 16, 2015 at around 5 pm.

This young Ficus tree on the west side of the street is staked and doing well; photo was taken April 16, 2015 around 5pm.

The older Ficus are doing well, though their canopies tend to be much wider nat-urally; photo taken March 16 around noon

This is the island planter in the loading area east of Point 5; Orchid trees are planted in mounds of slightly rangy Rosemary. These plants get a lot of sun and reflected heat from the pavement. The photo was taken April 16th around 5 pm.

This Fountain Grass is invasive and was probably not planted intentionally.

Close-up of the flowers on the unidenti-fied potted tree a few steps north of Point 1; photographed March 20, around 5 pm

The Date Palms are only located off of Mill at 7th Street, but they make a statement! Photo taken March 20 around 5 pm

A mix of annuals shares a planter with a young Ficus on the eastern side of Mill Ave; photo taken March 20, 2015, at 5pm

An Asparagus fern sits beside the thick trunk of a Ficus and shares a planter with annuals- photographed April 16 with flash

A healthy Pygmy Date palm sits in a stylish pot near Hayden Station; photo-graphed April 16, around 5 pm

Case Study: Mill Ave. & 3rd St. LRT Station

Plant ListTrees

Chitalpa (X Chitalpa tashkentensis)

Shrubs/ Accents

Red Yucca (Hesperaloe parviflora)Bougainvillea (Bougainvillea species, unknown cultivar)Compact Texas Ranger (Leucophyllum frutescens ‘Compacta’)Thread-Leaf Agave (Agave schidigera)Lady Banks Rose (Rosa banksiae, white variety)

Grass/ GroundcoverNone, only paving and decomposed granite

This small courtyard area connects the parking garage (left side of photo) with the office building; it has large metal sculptures and a grassy retention basin- March

These Bougainvillea get almost full sun, and are thriving. They do tend to shed their pink leaves quite often, but provide excellent shade nonetheless- April

Leaning toward the tracks, this Chitalpa seems to have been pruned to almost nothing, one branch at a time. This species seems to have trouble with branches snapping off; April

View (facing west) across Mill Avenue toward the LRT station; all photos were taken around 6 pm, though some were taken on March 20, 2015 and others were taken on April 16, 2015

View from the east end of the station, looking along the northern side; April

This Red Yucca was planted a bit too close to the sign; the plant will grow to 6’, but will prob-ably be harshly pruned to maintain visibility and increase pedestrian safety; April

Key Features Distinctive Shades unify all LRT stations & provide visual interest Vines growing between two screens within the shade structure provide shade and bright flowers Chitalpa Trees on the plat-form provide filtered shade and interesting flowers

What makes this site Harsh? This station experiences a lot of pedes-trian traffic, as well as reflected heat from the multistory buildings, asphalt, and all the paved surfaces. It is in a fairly urbanized location, and the planting spaces are not very generous. The buildings on the south side are tall enough to shade it for at least part of the day, and trash tends to accumulate in and on the planters.

Planting Details

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Unusually rangy Leucophyllum on the north side in the shade

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Left: Tree planted in an adjacent courtyardRight: Bougainvillea enveloping a shade sail

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Close-up of the same Chitalpa; it’s in bloom and the leaves are free of the white fun-gus that sometimes plagues these trees

The Leucophyllums on the south side of the station are doing very well, though they have caught the attention of the maintenance crew and have been pruned into the vague “trashcan shapes” endemic to nearly all public landscapes in Phoenix; April

Close-up of the trunk of the same tree- it is leaning in its grate and the metal is begin-ning to cut into it- this will cause damage

A Chitalpa on the northern part of the platform looks a bit sparse, and is leaning quite badly; April

These shrubs are fairly small; this planter gets too much shade to allow them to thrive like they do on the other side- April

The vine in the planter on the left is a Lady Banks Rose, but the one on the right is a Bougainvillea; the Lady Banks Rose vines do not seem to do very well in the hot Phoenix sun, particularly in summer. March

The Agaves and Hesperaloes appear to be doing very well, though some are planted too close together; March

The Hesperaloe is thriving, but it will eventually be trimmed. The sign may have come after the plant - March

These Chitalpas have delightful foliage, but they seem to be leaning to one side or an-other. They may have had branches pruned off, or the branches may have fallen off on their own. They sit in an at-grade planter that offers plenty of growing space; April

Pedestrians seem determined to put trash everywhere they can reach- even if they have to squeeze it into a screen!

The Bougainvillea at this station is very happy, as it blooms even at pedestrian eye-level (rather than only on top)- March

There are only a few blooms on the plant, but it may be too early in the season; the species blooms late spring- early summer

This Lady Banks Rose completely fills the space between the screens, providing gentle shade in the early afternoon- April

Close-up of Thread-Leaf Agave; it too catches leaves from the overhead vine that sits several feet south of it- April

A Red Yucca on the north side of the sta-tion; it is quite healthy, though it does get showered with Bougainvillea leaves; April

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Case Study: Veterans Way LRT Station

Plant ListTrees

Desert Willow (Chilopsis linearis)Desert Museum (Parkinsonia x ‘Desert Museum’)

Shrubs/ AccentsCreosote (Larrea tridentata)Cat’s Claw Vine (Macfadyena unguis-cati)Bougainvillea vine (Bougainvillea, unknown cultivar)Fountain Grass (Pennisetum setaceum)Pink Fairy Duster (Calliandra eriophylla)Engelmann’s Prickly Pear (Opuntia engelmannii)Brittlebush (Encelia farinosa)

Grass/ GroundcoverNone- only paving

View facing east from the western edge of the bus bay; a great deal of buses stop here, so pedestrian traffic can be intense. Photo taken March 20, around 6 pm.

Bronze sculpture near station seating; depicts a space commonly called the “Bunny Garden” that has 3 giant bronze rabbit statues. Photo taken (with flash) March 20, around 6 pm.

Bronze sculpture on a pedestal behind the seats; the building depicted is the Grady Gam-mage Auditorium, sans its entry wings. Photo taken (with flash) March 20, around 6 pm.

View (facing east) of the western part of the station, from the hiking trail at the base of Tempe Butte. Photographed March 20, 2015 around 6 pm.

Closer view of the poles and station structure, photo tak-en March 20, 6pm

View (facing northwest) from the first set of seats on the western part of the station; vines can be seen growing heartily up the structure. Photographed April 16, 2015 around 3 pm.

Key Features Unique Shade Structures unify all the LRT stops and pro-vide a gentle shade Art Pieces provide visual and tactile interest; the ones at this station have Braille plaques Spacious Paved Space- pro-vides ample room to handle the flood of transit riders, and words etched into the pavers make the space more interesting

What makes this site Harsh? It receives full sun, and it gets a huge amount of pedestrian traffic due to the fact that it is one of the stations used by ASU students in addition to other transit users. It has a lot of paving (reflected heat), and the plantings are always at risk of accumulating trash at their bas-es or in the foliage. It sits at the base of Tempe Butte, also known as “A” Mountain.

Planting Details

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Cat’s Claw Vine on some of the station shade structures

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Left: Desert Willow bloom. Right: Engelmann’s Prickly pear beside a service roadway.

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Cat’s Claw vine clinging to one of the shade structures; it’s not in bloom at the moment. Photo taken April 16, 3 pm

This was taken late April, 2015. The Desert willows are fairly close in size, and the vines are only slightly bigger. It seems that the vines on the western side (to the right in this photo) always have more foliage than those on the eastern side.

Bougainvillea vine at the west end of the station; it does not bloom on the lower portion. Photo taken April 16, around 3 pm

Desert Willow in full bloom on the south side of the station; photographed April 16, around 3 pm

Desert Willow, leaning slightly to the left, but otherwise healthy; photo taken March 20, around 6 pm

Trees are planted regularly between the shade structures; they are all young Desert Wil-lows that appear to be quite healthy. It can grow up to 30 feet tall, however, which may be problematic considering the height of the train wires. Photographed March 20, 6pm

Cat’s Claw Vine growing, protected be-tween two Green Screens of the shade structure; photographed March 20, 6 pm

A healthy young Desert Willow on the north side of the platform; photographed March 20, 6 pm

This photo was taken November 27, 2011 at 4:40 pm from the top of “A” Mountain. The Desert Willows are about the same size, and the vines are just beginning to flourish.

Engelmann’s Prickly Pear suffering from the reflected heat of the adjacent service road. Photographed March 20, 6 pm

Invasive Fountain Grass just past the end of the station; this was unintentional. Pho-tographed March 20, around 6 pm

Creosote in a planting space on the north side of the tracks; photo taken Spring 2014

Brittlebush growing beside the station re-taining wall on Tempe Butte; photo taken Spring 2014

Close-up of the same vine; the leaves are not quite as shiny or uniformly green as plant identification books depict

Cat’s Claw Vine growing on one of the shade structures; photo taken April 16 around 3 pm

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44Case Study: Tempe Transit Center

Plant ListTrees

Desert Willow (Chilopsis linearis)Desert Museum (Parkinsonia x ‘Desert Museum’)

Shrubs/ AccentsCreosote (Larrea tridentata)Cat’s Claw Vine (Macfadyena unguis-cati)Blue Elf Aloe (Aloe x ‘Blue Elf’)Soap Aloe (Aloe maculata)Candelabrum Agave (Agave bracteosa)Purple Heart/Wandering Jew (Tradescantia pallida)Rocky Point Ice Plant (Malephora lutea)Century Plant (Agave parryi v. couseii)Artichoke Agave (Agave parryi truncata)Unidentified Grass- bright greenUnidentified Grass- dark green, rather dense

Grass/ GroundcoverNone- only paving and decomposed granite

View (facing south) into the courtyard; these Blue Elf Aloes seem to be doing well. Photo was taken (with flash) on April 16, around 4 pm

One of the seating areas in the north side of the courtyard; photo taken April 16, 4 pm with flash; it looks dim nonetheless. The Gabion bas-kets are lit with colored LED’s at night

Blue Elf Aloes and Candelabrum Agaves cling to the gravel sides of their planters, beside the entrance to Copple Courtyard. Photo taken April 16, around 4 pm

View (facing slightly northeast) of the Transit Center and bus bay, from across the street. Photo taken April 16, 2015 around 4 pm.

View (facing south-west) of the Green Roof; taken late April 2015, around 3 pm

View (facing east) of the bus bay and the curv-ing sidewalk that borders it; the entire area is sloped. Photo taken April 16, around 4 pm

Key Features Unique Shade Structures unify all the LRT stops and pro-vide a gentle shade Art Pieces provide visual and tactile interest; the ones at this station have Braille plaques Spacious Paved Space- pro-vides ample room to handle the flood of transit riders, and words etched into the pavers make the space more interesting

What makes this site Harsh? It is located in an urbanized area of Tem-pe, and is used by hordes pedestrians and doz-ens of buses. Trash tends to get caught beneath the tree grates, where it is difficult to fish out. It generally does not get shade except for in the late afternoon. Copple Courtyard, which is di-rectly beneath part of the building, is constant-ly in deep shade.

Planting Details

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Cat’s Claw Vine on some of the station shade structures

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Left: Desert Willow bloom. Right: Engelmann’s Prickly pear beside a service roadway.

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This Agave parryi truncata is doing very well; photo taken March 20, 2015, around 6:30 pm

This was taken late April, 2015 from halfway up the side of “A” Mountain. The Green Roof is still thriving, and the Hesperaloes (both a red and a gold variety appear to be planted here) are in bloom! It is too far away to tell how the Pedalanthus are doing.

This planter is shared by several different species, and cleverly divided with low metal retainers to maintain the slope

The Candelabrum Agaves in the center of the planter are doing best; they might simply be out of reach of pedestrians

This planter is on the north edge of Cop-ple Courtyard- the Candelilia closest to the sunlight is doing best

The oddly angled planters are visually stunning, especially when the baskets are lit; the Agaves and Aloes closest to the low points seem to be doing better than their counter-parts closer to the top; all photos taken April 16, around 4 pm unless otherwise noted.

This Desert Museum is thriving in its raised planter, and has plenty of room to grow; it shades a large portion of the sidewalk too

This Desert Willow appears to have a very small tree grate; it may actually extend un-der the pavement to provide more space

This photo was taken November 27, 2011 at 4:40 pm. The green roof seems to be doing well, and the trees beside the courtyard appear healthy as well.

Bright green grass grows beside the dark green variety, separated by a thin metal divider (to retain the gravel grading)

Dark green bunch grass grows in the heavily shaded area of Copple Courtyard; it seemed to be doing quite well

The Soap Aloes growing in the planter in the 1st picture on this page are a bit dam-aged and brown upon examination

This Rocky Point Ice Plant seems to be getting by, but it looks like the tops of the leaves have been cut or damaged

The Agaves at the edge are within reach of pedestrians, and seem to get a lot of abuse; they are not doing very well

These Agaves are in a planter near a bus stop; the ones in the center don’t appear to be thriving (or are merely young)

46Case Study: ASU Biodesign Institute

Plant ListTrees

Velvet Mesquite (Prosopis veluntina)

Desert Museum (Parkinso-nia x ‘Desert Museum’)

Palo Brea (Parkinsonia praecox)

Ironwood (Olneya tesota)

Shrubs/ AccentsCreosote (Larrea tridentata)

Candelilla (Euphorbia antisyphilitica)

Aloe Vera (Aloe vera)Octopus Agave

(Agave vilmoriniana)Blue Elf Aloe (Aloe x ‘Blue Elf’)

Chuparosa (Justicia spicigera)Twisted Yucca (Yucca rupicola)

Organ Pipe Cactus (Stenocereus thurberi)

Desert Milkweed(Asclepias subulata)

Brittlebrush (Encelia farinosa)

Fishhook Barrel Cactus (Ferocactus wislizeni)

Silver Spurge (Euphorbia rigida)Toothless Sotol

(Dasylirion quadrangulatum)Deer Grass

(Muhlenbergia rigens)Parry penstemon(Penstemon parryi)

Yerba-mansa (Anemopsis californica)

Grass/ GroundcoverNone- only decomposed gran-

ite and concrete pavers

View along the northern side of the building; Twisted Yuccas in bloom and Mexican Honey-suckle sit in separated planters. Photo taken April 16, 2015 around 10 am

View along the east side of the building around 5 pm in early April; the Palo Verdes on the right are part of a nursery of trees for when the rest of the site is developed

Exposed aggregate concrete ramp leads from the secret garden up to the sidewalk next to the building; it is planted with Creosote and Brittlebush. Photo taken early April near 5 pm

View (eastward) along the southern end of the building, just east of the intersection of McAl-lister and Orange St; concrete benches sit be-side the sidewalk. Photographed April 2015

View of a Desert Museum rising from an Aloe Vera clump, April 2015

View of the sunken garden from sidewalk on the southeast corner of the building; the Mes-quites normally provide a light feathery shade. Photographed early April 2015 near 5 pm

Key Features Lush Plantings provide constant visual interest and sea-sonal blooms Sunken Garden- provides seating space and repurposes the AC condensate from the building Skyspace- an excellent space for meditation and passive observation of the beauty of the Arizona sky, especially at sunset

What makes this site Harsh? The building is 3-5 stories tall and located on the eastern edge of the ASU Tempe campus. It gets a lot of pedestrian traffic (there is a light rail station directly northeast of it), and the art installation “Skyspace” by James Turrell also brings in visitors. Most of the landscape faces east, but the western edge sits beside a fairly busy road (McAllister Avenue).

Planting Details

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Candelilia, Pedalanthus, and Creosote in stepped planters

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Left: Barrel Cactus w/view of Skyspace in back Right: Aloes and Candelilia on the east edge

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Parry penstemon near the Justicias in the previous photo; plantings are scattered and may be unintentional. April, 5 pm

The sunken garden’s retaining walls provide superb seating, and the sculptural Mesquites offer feathery shade. The plants surrounding the garden all look very healthy and lush. Photographed in early April, near 5 pm (the building is creating the deep shade).

These Mexican Honeysuckle are on the east side of the building near the sunken garden, and they look healthy. April, 5pm

The AC condensate feeds this clump of Yerba-mansa, which only has a few dead leaves. Photo taken early April, 5:30 pm

Planting detail to keep the Mesquites in the sunken garden healthy; they seem very happy. Photo taken early April, 5 pm

This photo was taken in Spring 2014, when the Aloe Vera was in bloom- the planting made the pedestrian feel immersed in the landscape. The Palo Verdes are placed amidst the Aloes, and all the plants are quite healty. The tips of the Aloes don’t bother pedestrians.

Yucca rupicola in bloom- these are on the north side of the building; the photo was taken April 16, 2015, around 10 am

These Desert Milkweeds on the north side get full sun mediated by the Palo Brea’s shade; photographed early April

This planter helps handle the grade change between the south side of the building and the street; it has Silvery Spurges (slightly small) on the top part and Desert Milkweeds (mostly healthy, some rangy) on the lower segment. Photographed early April, 5 pm

Organ Pipe Cactus grow along the west-ern edge of the building; they thrive in the sun. Photo taken early April, 5:30 pm

The Yucca rupicola plants are very healthy, sitting beside the sidewalk near the north-ern face of the building; April, 5:30 pm

Some of these Candelilia plants have sil-very branches, unlike the bright green ones at the south end of the building

The Candelilia is separated from the Aloe planting by a low divider; this is near the northeast entrance of the buildng

These Blue Elf Aloes sit beside the east-ern face of the building, interrupted by drainage ways; early April, 5:30 pm

These Aloes appear to be smaller than those beside the walkway, but they are healthy nonetheless. Early April, 5:30 pm

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Case Study: ASU Institute of Religion

Plant ListTrees

Monk’s Pepper/Chaste Tree (Vitex agnus-castus)Desert Museum (Parkinsonia x ‘Desert Museum’)Jacaranda (Jacaranda mimosifolia)

Shrubs/ AccentsJoshua Tree (Yucca brevifolia)Candelilla (Euphorbia antisyphilitica)Aloe Vera (Aloe vera)Regal Mist (Muhlenbergia capillaris Regal Mist)Lantana- Yellow (‘Pot of Gold’ Lantana)Lantana- Purple (Lantana montevidensis)Fox Tail Fern (Asparagus densiflorus Meyersii)Carolina Wild Petunia (Ruellia carolinensis) Note: this could also be Ruellia brittoniana; harsh pruning made accurate identification very difficult

Grass/ GroundcoverMost likely Bermuda (sunken beds at each corner)

View toward the southeast entrance from S. McAllister Avenue; the raised planter on the right side is planted with Joshua Trees and Lantana, in no discernable pattern

The building’s entrance along Orange Street (seen here from the east) features Palo Verdes in beds of Candelilla; the sidewalk is paved in brick interrupted with strips of concrete

The raised planter on the west side of the building contains an odd mix of Lantana and Joshua Trees, in a bed of decomposed granite- seen here facing south

View (facing east) through the walkway between the Institute of Religion and the parking garage to the north of it (seen here in the left portion of the photo)

Jacarandas, Aloes, and Lantana sit in at-grade planters along the walkway

View of the lawn on the northwest corner of the building, facing east; a ramp leads down to the neatly mowed grass sunken about 3’ below the grade of the regular sidewalks

Key Features Sunken Lawns at each cor-ner are striking, but don’t seem to be used by anyone Multiple grade changes to provide visual and experiential in-terest; stairs function as seating & possibly social space as well Raised planters showcase a few Joshua trees, and prevent the smattering of Lantana from being trampled by pedestrians

What makes this site Harsh? The landscaping for this site wraps around the building; it experiences all four exposures. It also sits amidst a sea of developed land- two edges border roads, and the other two are bounded by pavement and other buildings. The building immediately to the north is a parking garage, though the space between them may be wide enough to mitigate the excess heat.

Planting Details

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Small linear plantings beside the buildings tend to be shaded at least part of each day

6 9

7

9

48

View from the parking structure toward the northeast corner of the Religion building; receives eastern sunlight

The Vitex trees on the northeast corner of the building are nearly leafless, but have some green beginning to appear. The Euphorbia antisyphilitica, however, seem to be lackluster and possibly etiolated; it appears less healthy than those on the west side.

Jacaranda tree at northeast corner of building looks healthy; this plant receives eastern and western sunlight

Close-up shot of same plant, flash used to improve clarity; these plants receive gentle light and a fair amount of shade

Harsh pruning has left these Ruellias on the northeast corner of the building near-ly unrecognizable

Euphorbia antisyphilitica in bloom; located on the northwest side of the building. All photos taken on the same day, late afternoon in early April, 2015 unless otherwise not-ed.

Jacaranda tree in planter with aloes and lantana; on north side of building just west of the entrance/exit

Aloe vera about to bloom, lower leaves ratty; on western edge of north side of building closest to parking garage

Jacarandas along the walkway between the north side of the structure and the parking garage- the trees directly beside the parking seem to be dooing poorly; this may be due to reflected heat and southern exposure

The base of the tree is split, and a bit scarred. The Euphorbia antisyphilitica grows quite close to it

The Palo Verde seems moderately happy, if a little sparse; it may be pruned to pre-vent it from hanging down into the walk

Euphorbia antisyphilitica sit on either side of the south entrance; they seem to be in good shape

Asparagus ferns sit along the southeast corner; they get no western exposure at all, but face reflectd heat

Thus, the grasses don’t do as much to soften the edges of the architecture as the designer probably desired

The grasses around the sunken lawn tend to be harshly pruned so they don’t over-hang the walkway at all.

49

50APPENDIX A The email template below was sent to firms and individuals who had been selected to take the survey. In some cases, a firm would only allow contact through a “Contact Us” submission form on their website. These firms were sent the same letter, but it was copied and pasted into the form; none of the companies saw the large maroon and gold ASU symbol at the top of the form below (which only appears when an email is ‘printed’ from the server on the author’s end). The date on this form is May 8th, 2015, because that was the day I printed it from my email to include as an appendix in this document; the template itself was created in early February 2015.

APPENDIX B This was the 6-question survey sent out to 54 firms/individuals (in some cases the introductory email, at left, was sent to a firm’s general contact email, addressed either “to whom it may concern” or to a specific professional). The colors may have appeared differently to those who took it (it appeared gray when it was being formatted on the Survey-Monkey website), but the layout was the same. Question 6 was later changed to “would you be open to a follow-up interview held at your firm (or via telephone, if necessary)? Please provide your name (so I may track your responses), and if you are interested in the interview, please provide your address and contact information. Thank you for your time!” This was necessary after some of the responses came in with a simple “yes” in the response box - I couldn’t track or interview these people, as there was no way to identify them.

51 APPENDIX C This was the second email sent to survey-takers, politely reminding them to complete the survey if they had forgotten. The survey link was included to increase the likelihood of getting responses (it would be easier than asking the professionals to delve through a week’s worth of emails to find the original).

GENERAL CONSIDERATIONS & REQUIREMENTS Section 2-1

Design Standards & Policies ManualCity of Scottsdale - January 2010

Page 20

2-1.903 NATIVE PLANTS IN DETENTION BASINS AND DRAINAGE CHANNELSThe following is a guide in the use of native plants within detention basins and improved drainage channels:1. Plants that can be placed on the bottom of a basin:

• Velvet Mesquite (Prosopis velutina)• Four-wing Saltbush (Atriplex canescens)•Desert Hackberry (Celtis pallida)•Catclaw (Acacia greggii)*• Scrub Oak (Quercus turbinella)*•Chuparosa (Justicia californica)•Canyon Ragweed (Ambrosia ambrosioides)

2. Plants that may be placed on the sides of a basin:• (All plants listed above)• Ironwood (Olneya tesota)• Blue Palo Verde (Cercidium floridum)•Desert Willow (Chilopsis linearis)• Saguaro (Carnegiea gigantea)•Wolfberry (Lycium Sp.)•Desert Lavender (Hyptis emoryi)• Fairy Duster (Calliandra eriophylla)•Creosote (Larrea tridentata)• Jojoba (Simmondsia chinensis)*•Hopbush (Dodonaea viscosa)*•Mormon Tea (Ephedra trifurca)*•Cheese Bush (Hymenoclea monogyra)•Deer-Vetch (Lotus rigida)*• Sugar Sumac (Rhus ovata)*

3. Plants that should not be used in any part of a basin:• Foothills Palo Verde (Cercidium microphylla)•Chollas and Pricklypears (Opuntia Sp.)• Barrel Cacti (Ferocactus Sp.)• Bursage (Ambrosia deltoidea)•Century plants (Agave Sp.)• Brittlebush (Encelia farinosa)• Buckwheat (Eriogonum fasciculatum)•Ocotillo (Fouquieria splendens)

(*) - Plants that should be installed in locations above 1800 feet in elevation.

APPENDIX D This is the plant list page from the City of Scottsdale’s Design Standards & Policies Manual.

Plant Selection for Harsh Urban Environments in the Phoenix/Tempe Area

A Thesis Study by Erin Torchia, Candidate for Bachelor’s Degree of Science in Land-scape Architecture at Arizona State University

plant selection for harsh urban environments

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