CO

OPE

RAT

IVE

EXT

ENSI

ON

TH

E U

NIV

ERSI

TY O

F ARI

ZO

NA

Col

lege

of A

gric

ultu

re a

nd L

ife S

cien

ces,

P.O

. Box

210

036

• Tuc

son,

Ari

zona

857

21-0

036

ISSUED AUGUST, 2002

TOM DEGOMEZ, Associate Agent,

Agriculture and NaturalResources

ag.arizona.edu/pubs/garden/az1286.pdf

This informationhas been reviewed by

university faculty.

PUBLICATION AZ12868/2002

Ground Covers for Northern ArizonaAbove 6,000 Foot Elevations

Ground covers can be any low-growing,creeping, sprawling plant whose primarypurpose is to cover the ground in managedlandscapes. A wide range of plants can be usedas ground covers including smaller woodyshrubs, herbaceous perennials or even vines.Plants suitable for this use come in a wide rangeof shapes, sizes, textures, and colors. Manyproduce attractive flowers that add seasonalbeauty to their other good characteristics. Therequirements of a good ground cover are thatthey establish themselves quickly, are winter-hardy and form a thick, dense cover. Groundcovers provide attractive alternatives to turf,bare ground, and rock mulches.

Ground covers fill a number of important designneeds. They can form a low horizontal foliagemass that serves to organize or tie plantingstogether into a unified composition. Thistechnique is equally effective in plantings for one-story residences, tall office buildings or evenhighway embankments. They can soften and adda touch of greenery to the large rock-mulched areasso often seen in low water use landscapes. Largeexpanses of paving also look cooler and moreinteresting if beds of ground covers areoccasionally substituted for sections of pavement.From a practical standpoint, groundcovers thatroot along the ground as they grow can controlerosion on steep slopes. Mowing turf on small orodd shaped areas or on steep banks or moundscan also be eliminated with ground coverplantings.

Ground covers differ in the amount of foot trafficthey tolerate without injury. None can withstandthe heavy use given turf grasses, but a few speciesare adapted to light traffic. Some species growwell between flagstones; the stones protect thecrowns of the plants from injury.

Many ground cover beds will develop barespots or areas of sparse open foliage within twoto four years. This may be due to weather,cultural practices, pests, or the gradual changefrom vigorous young leafy plants to older lessdensely foliaged plants. Regular maintenance isthe key to keeping plants dense and vigorous. Inaddition to proper irrigation, fertilization, andpest control, it may be necessary to replant barespots and pruning or mowing old stems tostimulate new growth.

Many gardeners attempt to establish denseground cover plantings in areas that receive littleor no supplemental irrigation. This is nearlyimpossible to accomplish, even with droughttolerant species. The nature of a drought tolerantplant is to grow with lots of open ground inbetween. Low water-use ground covers willassume a similar growth pattern if they mustsurvive and grow with natural precipitation only.Supplemental irrigation is required for solidfoliage cover even with arid plant types.

General planting instructionsThe best planting times are from July to early

fall. Plants set out during this time will receivethe benefits of the moist summer rainy season.Plants can be set out in May and June but theymust be carefully watered, often on a daily basis,due to dry, windy conditions that persist duringthese months. Plants set out in mid to late fallmay not have a chance to develop adequate rootsystems prior to the onset of freezing weather.

Adequate soil preparation is essential forestablishing a ground cover quickly. The groundmust be free from perennial weeds. Creepingweeds with rhizomes or stolons can beparticularly troublesome. A chemical weedcontrol, hand weeding or the use of fabric orplastic mulch may be required.

Most Northern Arizona soils are limited in theamount of organic matter that they contain.Adding organic soil amendments such asdecomposed bark, compost or well-rottedmanure greatly improves these soils andpromotes the establishment of new plants.Spread a 2 to 3 inch layer of one of thesematerials and spade or rototill into the soil 8 to12 inches deep. If the terrain makes itimpractical to work the entire area as describedabove, prepare individual planting holes aswide as possible (at least 3 to 5 times the widthof the root ball of the plants to be planted).These holes should only be as deep as the rootball of the plants to be set out. Back fill with amix of native soil and organic matter.

Ground covers are often used in areas wheregrowing conditions are less than ideal. Theymay be planted on steep dry slopes in full sun ordeep shade. In addition, most types grow closeto the ground where they are exposed to a

2 The University of Arizona Cooperative Extension

microclimate of extremes of heat or cold. This makes goodsoil preparation essential to plant establishment andgrowth.

Careful spacing of ground cover plants can ensure quickcover. The recommended spacing for most plants is just alittle less than the spread of a mature specimen. Forquicker coverage, space ground cover plants so that theywill cover the site in one or two growing seasons. This willbe about two-thirds their mature size. More plants may beneeded but this practice may reduce weed controlproblems and usually results in a smoother cover with nomounding by individual plants. When ground covers areplanted at the correct distance, there will still be bareground between them. Mulching the gaps with woodbased mulch or pine needles will help to retain moistureand discourage the growth of weeds. Landscape fabric canalso be used.

Set the plants at ground level and gently firm backfill soilaround the roots. On banks and slopes, leave a shallowbasin around the root ball of each plant to hold irrigationwater.

Perennial weeds are a prime cause of failure in plantingand maintaining ground cover beds. They are notimpossible to control if the bed can be kept clean until athick dense planting exists. Weeds are less likely to invadeonce ground covers fill-in the bare spaces between plants.Chemicals are available for establishing a relatively weed-free planting site. In most cases however, two or moretreatments must be made during summer to rid an area ofexisting weeds.

Tender ground cover nursery stock dies quickly ifallowed to dry out on the planting site. It is important thatplants be watered thoroughly a short time before beingremoved from growing containers and placed in theground. Irrigate the bed area several days before plantingso that the transplants will be set in moist soil. Since it maytake several hours or longer to complete the plantingoperation, the first plants set out may become dry beforethe job is finished, especially on warm, windy days. Toprevent such losses, stop at regular intervals to watertransplants.

Young ground cover plants are shallow rooted and mayneed watering every two or three days for the first two tofour weeks after planting. When established, the sameplants may require watering every 5 to 10 days in hot dryweather, but only every 2 or 3 weeks during the rainyseason or in the fall.

Care of established plantingsIrrigation — Watering ground covers on slopes ofteninclude the problem of surface runoff with poor infiltrationof moisture to the depth of plant roots. Whatever thesystem used, apply water only as rapidly as the soil willabsorb it. It may be necessary to irrigate for several briefperiods with time between each cycle to moisten the entireroot zone without wasteful surface runoff. A dripirrigation system is perhaps the most efficient way to waterground covers on slopes. Also, many ground coversshould be watered on a different schedule than turf, so

their irrigation system should be separate from the lawnarea.Fertilizing — Since ground cover plants grow in closecompetition for nutrients, they should be fertilizedregularly to maintain good leaf color and moderategrowth. Overfertilization results in excessive growth thatrequires more work to maintain and keep attractive.Fertilize established ground cover planting at least onceeach year in late winter or early spring.

Nitrogen is usually the key element that must besupplied. The percentage by weight of nitrogen in afertilizer is indicated by the first number in the analysis,such as 20-10-15, 16-20-0, etc. This information is printedsomewhere on the fertilizer container. A typical fertilizerrecommendation for mature ground covers is two poundsof ammonium sulfate (21-0-0) per 100 square feet. or othergarden fertilizer applied uniformly when the foliage is dry.Then water thoroughly to wash off any fertilizer particleslodged in the plant foliage and to move the nutrients intothe plant root zone.Pruning and mowing — Some ground covers may requirepruning or mowing to look their best. Wait till danger offrost is over before cutting back tender species. Rapid-growing types may need trimming two or three timesduring the growing season. The appearance of theplanting will usually serve as a guide for schedulingpruning work. To encourage ground cover beds to recover,quickly fertilize and irrigate after pruning is done.

How to select a ground coverThree basic questions should be considered when

selecting a ground cover:1. Will this plant create the desired landscape effect?

(Consider mature height, growth habit and growthrate, texture, color, bloom period, year-roundappearance.)

2. Will this plant grow well on the site? (Consider soiltype, topography, soil and air drainage, lightexposure, seasonal high and low temperatures, waterrequirements, hardiness.)

3. Will this plant make an attractive ground cover withthe maintenance I can provide? (Consider irrigationand fertilization requirements, pruning or mowing,pest control, life span and replacement needs.)

The following table lists some of the most useful groundcover species for Northern Arizona above 6,000 feet inelevation as well as their landscape uses and culturalrequirements.

Explanation of cultural requirements used inthe ground cover table:

WaterHeavy —Plants thrive in or when adjoining lawnconditions. This implies that upper root zone soil is keptmoderately moist at all times.

The University of Arizona Cooperative Extension 3

Issued in furtherance of Cooperative Extension work, acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture, James A.Christenson, Director, Cooperative Extension, College of Agriculture, The University of Arizona.The University of Arizona College of Agriculture is an Equal Opportunity employer authorized to provide research, educational information and other servicesonly to individuals and institutions that function without regard to sex, race, religion, color, national origin, age, Vietnam Era Veteran’s status, or disability.Any products, services, or organizations that are mentioned, shown, or indirectly implied in this publication do not imply endorsement by The University of Arizona.

Moderate — Plants thrive with deep irrigation spaced 7-17 days apart depending on season and type. Surface layerof soil may dry out but adequate moisture levels arealways maintained in deeper root zones.Low — Plants tolerate long dry periods but must bewatered deeply on an occasional basis to grow or developand during periods of extreme drought. This groupincludes most of the true natives.

ExposureShade —Area receives no direct light such as under a roofor dense tree canopy. There is a range between deep shadesuch as under a solid roof and open shade - for example thesituation found in the shadow side of a tall building wherethe sun never penetrates and yet there is open sky above.

Partial shade —Situation under trees where there is adappled sun and shade pattern or a situation where thereare few hours of sunlight early or late in the day. Lateafternoon sun is more intense and is usually accompaniedby a heat build-up. Plants requiring part shade often donot thrive in locations with intense afternoon sun.Full sun —Area receives direct unobstructed sunlight formore than half of a day. There is a range between directsun and reflected sun, planting areas close to walls facingsouth or west are much hotter. These situations may limitthe use of certain plants which are sensitive to reflectedheat.

4 The University of Arizona Cooperative Extension

EMAN &THGIEHDAERPS

NUS RETAW SKRAMER

deewtuoGs'pohsiBairargadopmuidopogeA

"81-21X"21-6

tnarelotthguorddehsilbatseecno

egailofdnuopmocsahtahtrevocdnuorgevisserggA.sevaelehtnonoitageiravdegde-etihwhtiw

rofnworG.smetsdnuorgrednuybylisaesdaerpSlliwegailoF.srewolfetihwehtton,egailofeht.yrderasliosnehwronusllufnisegdetanworb

elguBtepraC,deewelguBsnatperagujA

"42X"21-6

tnarelotthguorddehsilbatseecno

eulbroknip,etihwhtiwrevocdnuorgworg-ot-ysaEotneergpeedsiegailoF.gnirpsetalnisrewolf

kcihtasmroF.ravitlucnognidneped,detageiravdaerpslliW.htiwetepmoctonnacsdeewtahttam

.ylralugerderetawfiyldipar

dloG-fo-teksaB)silitaxasainiruA.nys(elitaxasmussylA

"81X"21

srewolftubhtiwtsebetaredom

.retaw

wolleythgirbsraebtahtrevocdnuorgetartsorPkcorrofeciohcdooG.gnirpsehtnisrewolfwolA.redrobehtfotnorfehtrofrosnedrag

erastnemeriuqerylnosti,tnalpecnanetniam4yrevenoisividdnagnirewolfretfagninurpthgil

.sraey

seotyssuPailofivrapairannetnA

"81X"01-4 rofdesusitahtrevocdnuorgevitangnimroftaMdnaslioselitrefnifotnareloT.egailofyargsti

.edahstrapnitsebsiseicepssihT.snoitacolyrdelttildnanusllufeldnahnacseicepsrehtO

.retaw

yrrebraeB,kcinnikinniKisru-avusolyhpatsotcrA

'51X"6-2

ecnodehsilbatse

neergthgirb,yssolghtiwneergreveetartsorPderotknipdnasrewolfknipotetihw,sevaelotylkeewretaW.detratstegotwolS.tiurf

.ylhtnomneht,hsilbatse

doowmroWhcaeBanairelletsaisemetrA

"81X"6-4 ,debolhtiwrevocdnuorggnidaerps,wolAytsudgniworgwolaselbmeseR.egailofyrevlis

gnirewolfretfayletaidemmidaeh-daeD.rellim.koolekil-gurehtniatniamot

remmuS-ni-wonSmusotnemotmuitsareC

"63-42X"6 fostolhtiwrevocdnuorggnimrof-tamwoL,yllooW.remmusylraenisrewolfetihwllams

deretawfiylkciuqsdaerpS.egailofyrevlisliosyrdhtiwnusllufnitsebskooL.ylraluger

deesfideesfleslliW.ytilitrefniwolsitaht.notfelsdaeh

elimomahCnamoR)silibonsimehtnA.nys(elibonmulemeamahC

"81X"21-3

ylthgilsretawwol

ylenifhtiwlainnerepneergrevesemitemosAdepahsnottubetihW.sevaelcitamora,tuc

.dewomebnaC.remmusniraeppasrewolf.ciffarttoofemoseldnahnaC

retsaenotoCkcoRsilatnozirohretsaenotoC

'5-3X"63-42 delgnaylffitshtiwburhsgnidaerpssuoudiceDemitgnolaroftnalpnoyatssevaeL.sehcnarb

gnillaferofebdernehtdnaegnarogninrut,llafni.daerpsotmoortieviG.tiurfderynihS.ffo.sehcnarbfosdneenurpt'nod,kooltsebroF

tnalPecIelpruPydraHirepoocamrepsoleD

"42X"5-3 tahtsrewolfelprupgninihshtiwydrahyreVotylsuorogivsdaerpS.gnolremmusllaraeppa

.sevaelneerg,tneluccusfotamesnedamrof

tnalPecIwolleYydraHmunegibunamrepsoleD

"42X"2 wolleythgirbhtiwstnalpecillafotseidraHehtnidernruttahtsevaelneergdnasrewolfllamsfosderdnuhhtiwderevocsitnalP.llaf

.gnirpsetalnisrewolf

repeercretniW,sumynouEienutrofsumynouE

'6-3X'3-1 tahtburhsneergrevedevael-daorbgniworgtsaFnielbaliavA.steltoorybsbmilcrosdaerps

ydniwdiovA.smrofyhsubrognidaerps.nworbnrutlliwegailofretniwsasnoitacol

Table 1. Ground covers for northern Arizona

Low Moderate Heavy Shade Partial shade Full sun

The University of Arizona Cooperative Extension 5

EMAN &THGIEHDAERPS

NUS RETAW SKRAMER

sdooW-eht-fo-retsaM,ffurdooWteewSmutarodomuilaG

"21X"8-6 smroftahtegailofnoyaMnisrewolfetihwyniTsdaerpS.slosaraperutainimekildepahsslrohw

dnuorgdooG.erutsiomfostolnevignehwylkciuq.sevaeltnargarF.seertrednusaeradedahsrofrevoc

htaerBs'ybaBgnipeerCsneperalihpospyG

"21X"6-3 llamshtiwderevocsitnalp;revocdnuorglufituaeBknipA.tsorflitnugnirpsetalmorfsrewolfetihw

snedragkcorroftnalpelbaulaV.elbaliavasiravitluc.liosdeniard-llewaseriuqeR.sllawyrddna

yvIhsilgnExileharedeH

''5X"8-6 otworgylkciuqnactahtenivneergreve,ydooW,secnef,sllawnosgnilcdnasbmilC.eromro'05

nehwtsebtubedahsronuS.cte,sesillertfostolsdeeN.dediovasinusnoonretfa

tubdetnalpnehwrettamcinagrodnaerutsiom.dehsilbatseecnotnarelotthguordylriaf

tA.negortinfognideeftsuguAmorfstifeneBdnadniwretniwtsniagatcetorpsetistsedloc

.nus

tfutydnaCneergrevEsnerivrepmessirebI

"42X"21-6 etihwthgirbhtiwsdnuomneergrevewoL.regdenasatnellecxE.gnirps-dimnisrewolfotgnimoolbretfaffoderaehsebdluohsstnalP

.retniwehtninworbnrutyaM.taenmehtpeek

repinuJtepraCsilatnozirohsurepinuJ

X"21otpUnosdneped,'01

ravitlucthguordyrev

tnarelot

nahtrellatgniworgylerarsrepinujgniworgwoL.tibahgnihcnarbdnarolocegailoffoegnaR.'1

doogatlusnoc;elbaliavaerasravitlucynaMepytliosynA.scitsiretcarahcravitlucnoyresrun

.sliosdeggolretawtpecxe

eltteNdaeDdettopSmutalucammuimaL

"81X"6

tnarelotthguorddehsilbatseecno

setarelottahtrevocdnuorggniworgtsaf,ydrutS.edahsdna,slevelerutsiom,sliosfoegnarediwa

evobayaMniraeppasrewolfelprup-hsikniPfievisavniemocebnaC.sevaeldehctolbetihw

.lioselitreftsiomninworg

elkcusyenoHesenapaJacinopajarecinoL

'51otsbmilCeromro

ruonisuoudicedsitahtenivneergreve-imeSthguordylriaftubretawremmusegarevA.aera

tnapmarebnaC.dehsilbatseecnotnarelotetalnisrewolftnargarF.snoitidnoclaedirednukciuqrorevocdnuorgdooG.remmusotgnirps

.debarevoekatlliw,suorogivyreV.neercs

ainohaMgnipeerCsneperainohaM

"63X"21 ,tibahgnidaerpsahtiwsburhsneergrevEwolleY.semozihrdnuorgrednuybgnipeerc

stiurfkcalb-eulbybdewollofgnirpsnisrewolfrednudnuoF.sdribotevitcarttaerataht

.tnarelotthguorD.senipasorednop

tnimtaCiinessaafxatepeN

"81X"81-21

eromsrewolftubetaredomhtiw

retaw

revosemecaresoolnidlehsrewolfeulbelaPnedragtnasaelpasihtekamegailofyriah,yargtisatnalpgnigdenasanworgnetfO.noitiddadnuorgmorf"8egailofraehS.edacsacotsdnet

.moolbremmusetalrofremmusylraeni

repeerCainigriVailofeuqniuqsussiconehtraP

rosbmilCro'02sdaerps

erom

laireahtiwsgnilctahtenivsuoudicedsuorogiVserutcurtsnedoowraentnalptonoD.slirdnet

ehtnidersnruT.evomerotdrahebnactisa.P.seirrebnmutuaeulbehtekilsdriB.llafevahtonseodtahtmrofnretsewasiatresni

.steltoorlairea

gnirewolF,xolhPniatnuoM,kniPssoMssoM

atalubusxolhP

"42X"6-3 tepracaedivorpsrewolfelprupro,etihw,kniPneergrevesiegailoF.gnirpsylraenirolocfo

tsomladnaffits,worrangniebsevaelhtiw-llew,ynnusanirevocdnuorgevitceffE.ylkcirp

tuC.snedragkcorrofdooG.etisdeniardesnedetomorpotgnirewolfretfakcabegailof

.egailof

Low Moderate Heavy Shade Partial shade Full sun

6 The University of Arizona Cooperative Extension

EMAN &THGIEHDAERPS

NUS RETAW SKRAMER

liofeuqniCgnirpS)anrev.P.nys(inatnomeanrebatallitnetoP

"81X"9-6 llafdnaremmusnisrewolfpucrettubwolleythgirBylriaF.egailofekil-yrrebwartsfotamanroda

erutsiomsekiltubdehsilbatseecnotnarelotthguord,etartsorpybsdaerpS.nusllufninworgnehw

.smetsgnitoor

rednevaLnottoC,anilotnaSyarGsussirapyceamahcanilotnaS

"63X"81 .egailofyarg-revlisdnasrewolfnottubwolleYdnataengnikooltispeeksrewolfdedafgniraehS

sahsneriv.S.gnirpsylraerofepahsehtpusnethgit.yargehtsaydrahsaetiuqtonsidnaegailofneerg

.liosydnasanitsebsworG

trowpaoSsediomycoairanopaS

"42X"01

eromsrewolftubetaredomhtiw

retaw

asecudorptahttnalptcapmocworgotysaE.remmusdnagnirpsetalnisrewolffonoisuforp

derewolfetihwasi'ablA'tubknipyllaususrewolFtseB.owtroraeyaniezisllufsniattA.ravitluc

niro,revocdnuorgasa,sllawkcorrevognidacsac.redroblainnerepehtfotnorfeht

porcenotS.ppsmudeS

-21X"8-2gnidneped"81

seicepsno

sekiL.smetsgniliarthtiwtnalptneluccus,ydraHtahtsevaeletunimsaherca.S.liosdeniard-llew

ehtfoenosi'doolBs'nogarD'.neergthgileraetalnisrewolfder-esorstihtiwralupoptsom

seicepsrehtoynaM.sevaeleznorbdnaremmus.elbaliava

raEs'bmaL-)anatnal.S.nys(anitnazybsyhcatS

-21X"81-21"63

ylloowhtiwrevocdnuorgeerferac,suorogiVrewolfllaT.tamesnedamroftahtsevaeletihwyaM.srewolfcalilllamsfosderdnuhevahsekips-nonasi'tepraCrevliS'.sniaryvaehretfa'tlem'nidnagnigderoftnalpdooG.ravitlucgnirewolf

.redrobehtfotnorf

emyhTyllooWsusonigunalsumyhT

"81X"2 htiwyteiravecnanetniamwol,gnigguhdnuorGA.srewolfyleraR.sevaelneerg-yargynit

toofthgilekatnaC.senotsgalfneewtebetirovafhtaenebedahsthgilyrdniworglliW.ciffart

.seert

emyhTgnipeerCmullypressumyhT

"81X"3

emostubekatsravitlucedahslaitrap

deenemosretawetaredom

neergkradhtiwemyhtrevocdnuorgywohSotetihwmorfgnignarsrewolfynamdnasevael.senotsgalfneewteblecxesravitlucemoS.esor

.ciffarttoofthgilseldnaH

acinoreVatanitcepacinoreV

"42X"4 esnedhtiwrevocdnuorgetartsorpsuorogivAfosekipshcni-ruoF.egailofneerg-yargylloow

yaM.gnirpsniraeppasrewolfeulbpeedthguordtsoM.retawartxehtiwmoolberrehtO.sacinorevgnipeercehtfotnarelotdoogsekiL.elbaliavaeraseicepsgnipeerc

.eganiard

acniVroelkniwirePronimacniV

X"21-6gnidaerps

thguordtubecnotnarelot

dehsilbatse

,ynihsevobagnirpsnineposrewolfeulBraeppanacsrewolF.egailofneergreve

tiesuacebdesuylediW.remmusllayllacidaropssdaerpS.elbatpadayrevdnaworgotysaesi

llatatoorhcihwsmetsgnirewolf-nonybylkciuqdnuorgasa,lortnocnoisorerofdooG.sedon

.sblubgnirpsrofrevocasadnarevoc

Low Moderate Heavy Shade Partial shade Full sun