JazzyLouisiana Irises

Shapely blooms and Mardi Gras colors spice up gardens north and south

Fine Gardening 22

S a child I grew up alongside thebearded irises and wildflowers my

mother raised each year. They were almostlike family. Then, about the time of my25th birthday, I moved from hot, dry Dallas to steamy, southern Louisiana.When the damp, humid climate of my newhome proved intolerable for my belovedbearded irises, I had to make a dire deci-sion. I could either head back to Texas, or I could try my hand with a beautifulwildflower native to the Gulf Coast—theLouisiana iris. Luckily, I chose the iris.

I liked Louisianas right away for theirvivid yellows, bright blues and rich brickreds; for the fact that they were natives;and, finally, because they seemed so neglected. Gardeners paid them so little attention that it was as if the flowers need-ed somebody to help them along. That’swhere I came in.

I recognized their potential. They are easyto breed, easy to grow (they thrive as farnorth as Canada) and, of course, they arebeautiful. We got along famously.

AN IRIS AT HOME ALMOSTEVERYWHERE IN THE GARDENI grow most of my Louisiana irises with an-nuals and other perennials in regular flowerbeds, along borders, and in with my vegeta-

July�August 1996 23

A wonder in water gardens, Louisianairises are naturally a water or bog plant.The author showcases yellow ‘ProfessorBarbara,’ red ‘Professor Neil’ and rose‘Professor Marta Marie’ in her own pond planting.

by Marie Caillet

A

All photos, except where noted: Charles Mann24 Fine Gardening

bles. My most dramatic plantings are at theedges of a small pond that was once an over-grown mess (photo, p. 22).

I have a very informal garden that is oftencompared to English cottage gardens. Theiris beds are also filled with larkspurs,Coreopsis, Penstemon, periwinkles andspider lilies (bottom right photo, facingpage). To add to the informal look, I allowannuals such as old-fashioned petunias, an-nual poppies and Johnny jump-ups to re-seed throughout (photo, left). Most bloomabout the same time as the Louisiana irises. Perennials like daisies, phlox anddaylilies add to the color and extend thebloom into summer. Daylilies are especiallydesirable since their bloom begins just asthe irises finish.

LOUISIANA IRISES COME INSCORES OF SHAPES, SIZES AND COLORSLouisiana iris is the collective name for fiveiris species native to boggy coastal areasfrom the southern Atlantic states into Central Texas. They interbreed easily, andtheir many hybrid offspring—whether thework of botanists or of nature—are alsoknown as Louisiana irises.

The common name comes courtesy ofnaturalist and wildlife artist John JamesAudubon, who painted the brick-red Iris

fulva into the background of a portrait ofthe Parula warbler (illustration, aboveright). He identified the bloom as aLouisiana iris. The name stuck.

Each of the five original Louisiana irisspecies contributes a special quality to thehundreds of hybrids now on the market. The tallest I. giganticaerulea, grows up to5feet. It is an early bloomer with white toblue-purple flowers. I. brevicaulis, alsowhite to blue, is a very late bloomer andgrows under 2 feet tall. Another latebloomer, the slightly taller I. hexagona, hasflowers in the same color range. The speciesof I. fulva and I. nelsonii contribute the bril-liant reds and yellows for which Louisianairises have become known. No other nativeiris started with this intense red color. Withblooms in the primary colors of red, yellow

and blue plus the native whites, Louisianairises can be crossbred to make almost anycolor. There are blends such as ‘Just He-lene’, bi-tones such as ‘Kristi G’ and near bi-colors like ‘Colorific’. A signal patch mark-ing—a colored swatch found on nearly allwater-type irises—adds a splash of yellow or orange to the falls, the outer part of theflower, and sometimes to both the falls andthe standards, the flower’s inner petals(bottom left photo, facing page).

There is also extensive variety in flowerforms. Some have upright standards andflaring falls like bearded irises. One ofthem, ‘Kristi G’, has a flaring form I call a

July�August 1996 25

Louisiana irises command attention evenin an informal setting. White Shasta daisiesand pink phlox help create a bright backdrop (above).

Create a memorable composition withWestern spider lilies and a splash of‘Colorific’ Louisiana irises (near left). In thebackground, bursts of Penstemon breakthrough thickets of swordlike iris foliage.

Like bright jolts of electricity, streams ofwhite emanate from the center of a ‘VioletRay’ (far left). The ray pattern of colors istypical of many water-loving irises.

L O U I S I A N AI R I S

(Iris fulva, I. giganticaerulea, I. brevicaulis, I. hexagona,

I. nelsonii and their hybrids)

◆ Herbaceous perennial hardy to USDAHardiness Zone 4 (–30°F)

◆ Excellent in water or bog gardens

◆ In beds, prefers neutral to acid soil, andthrives with a half day or more of sun

◆ Use mulch to keep soil moist and protectrhizomes from sunburn

◆ Plants spread quickly from rhizome

I llustration, top right: John James Audubon; courtesy of Mill Grove, The Audubon Wildlife Sanctuary, Montgomery County, PA

“butterfly” (photo, above). Others, such as‘Delta Star’, have flower parts flat as cart-wheels. Still others resemble Japaneseirises, with the standards and falls hanging like a pendant.

A few cultivars have extra petals orpetaloids, giving a double effect—‘DoubleTalk’ is a prime example. Others, such as‘Bayou Fountain’, are ruffled or have lacyedges. The size of flowers ranges fromabout 4 inches across to the 7-inch-across‘Aunt Shirley’, named for my sister.

The variations are endless. Characteris-tics such as height, color, markings andflower form are limited only by the imagi-nation of modern hybridizers. About 500different cultivars are currently available,but more than 1,000 have been registered.

LOUISIANA IRISES ARE EASY TO PLEASEThese so-called “Southern State Irises”adapt to garden situations from Canada to Arizona. The rhizomes and foliage

are almost disease-free if given good cul-ture. Louisiana irises are hardy to USDAHardiness Zone 4, with some record ofsuccess in even colder areas. They aregrown on every continent save Antarctica,and have become one of the most popularirises in Australia.

Cultural requirements for Louisiana iris-es are simple: at least a half day of sun, aneutral or acidic soil, and plenty of fertiliz-er and water. They will grow almost any-where, but very sandy or heavy clay soilsshould be amended with humus, such aspeat moss, compost, bark mulch or rottedhay. Since Louisiana irises are naturally awater or bog plant, they excel in water gar-dens. The constant moisture keeps the rhi-zomes cool and prevents them from dryingout when the plant’s growth slows duringhot Texas summers. If the rhizomes do dryout, the plant’s growth suffers in fall and itmay not bloom the next spring.

Late summer and early fall are the besttimes to plant or transplant Louisianas, but

planting is also possible right after bloom.New growth appears in fall, and in mildwinters the foliage remains erect and green.

Most gardeners purchase Louisiana irisesthrough mail order. Rhizomes are usuallyshipped moist and are wrapped in a plasticbag. On arrival, you should remove themfrom the bag and place them in water torehydrate overnight. Never allow the rhi-zomes to dry out.

Louisiana iris rhizomes should be plantedat least 1 inch under the soil, then toppedoff with 2 to 4 inches of compost or othermulching material. I like to use pine nee-dles because they do not pack down orwash away with heavy rains. Once in theground, new plants should be well watereduntil new roots begin to grow.

Mulch helps hold moisture and keeps thesun from scalding the rhizomes. I keep sixcompost bins full of oak leaves, pine nee-dles, old flowers and even weeds, and usethe compost to enrich beds prior to fallplanting or as a mulch during the summer.Growers in colder climates will need tomulch during the winter.

Louisiana irises do not form compactclumps like Japanese and Siberian irises. In-stead, they spread out as they increase,moving away from the initial rhizome. Tokeep cultivars separate for easier identifica-tion, space plants 2 to 3 feet apart. For aninstant garden effect, group several differ-ent cultivars more closely.

Irises need fertilizing about four to sixweeks before bloom to ensure sturdy stalksand good flowers. Established plants thatare not being transplanted also need to befertilized in late summer or early fall. I rec-ommend a regular balanced garden fertiliz-er or an acid type sold for camellias and aza-leas. I also like some of the water-solubleacid-type spray fertilizers on the market.

TURNING A SWAMPY,OVERGROWN EYESORE INTO A SHOWCASE FOR IRISESMy real showstopping display of Louisianairises came about almost by accident. Thirty-five years after discovering the wild-flower, I retired and moved back to north

26 Fine Gardening

A namesake for four cultivars of Louisiana iris, author Marie Caillet was attracted to these Gulf Coast natives long before they became popular garden plants. Here, she stands by a clump of pink ‘Kristi G’.

A treasury of garden-worthyLouisiana irises

It’s hard to pinpoint whatmakes some Louisiana iriscultivars more appealingthan others, but most ofthose listed below havebeen in my garden for along time. Some I’ve usedto create whole land-scapes. Others just seemto grow exceptionally wellin my north Texas garden.Any list like this mightchange from year to year,but last season, theseflowers caught my eye:

� ’Cajun Sunrise’—Themost photographedLouisiana iris in my gar-den, this breakthrough

in color features brown-ish-red flower partsedged in yellow.

� ‘Colorific’—Lavenderfalls, nearly white stan-dards and a greenthroat make this excel-lent grower a standout.

� ‘Crisp Lime’—This ruf-fled white flower has agreen throat.

� ‘Delta Star’—This cart-wheel-shaped flower isdark purple, with narrowyellow signals. It growsespecially well in water.

� ‘Dixie Deb’—This oldcultivar makes an excel-lent garden flower. It’stall but well propor-tioned, with medium-sized yellow blooms. Itincreases well and grows under almost all conditions.

� ‘Dural WhiteButterfly’—Ruffledwhite blooms open in aclump atop this medi-um-height iris.

� ‘Feliciana Hills’ and‘Aunt Shirley’—Thesemedium-height and tall (respectively) cultivarsare grown for theirlarge, showy pink flow-ers.They increase well.

� ‘Grace Duhon’—As oneof the darkest purples inthe garden, the bloomsof this cultivar providean excellent contrast tolighter-colored flowers.

� ‘Kristi G’— This latebloomer has large, pink-ish-lavender flowers; anexcellent grower in bogs

and regular flower beds.

� ‘Marie Caillet’—This oldcultivar, named after me,grows and blooms un-der almost any condi-tions. Its blue-purpleflowers appear on tall,branching stalks.

� ‘Marie Dolores’—Thisexcellent grower isbeautifully branched. Itsflower is white with ayellow-orange signal.

� ‘Mrs. Ira Nelson’—Slightly ruffled, flaringlavender flowers charac-terize this old cultivar.

� ‘President Hedley’—One of the few gold-colored Louisianas, thisexcellent grower has a Japanese-typependant form.

� ‘Professor Fritchie’—Blooms of this tall andstately iris tower asmuch as 5 feet abovethe pond. It is one of the hardiest of thetetraploid varieties.

� ‘Professor Ike’ and ‘Pro-fessor Claude’—Theselarge reddish-purpleblooms with yellow sig-nals were the first Loui-siana-iris tetraploids.

� ‘Professor Neil’—Excellent color is thehallmark of this reddestof red Louisianas. Itsflower is marked by abright yellow signal.

� ‘Rose Cartwheel’—Thisdesirable garden flowerhas narrow fronds offoliage and flat, rose-red blossoms. —M.C.

As the reddest of the Louisiana irises,‘Professor Neil’ is something of a curiosity.This cultivar is one of the recently devel-oped tetraploids, genetic treasuries thathybridizers hope to use in the developmentof even more abundant diversity amongLouisiana irises.

The ‘Delta Star’ shines bright. This tall,cartwheel-shaped variety stands nearly 4 feet off the ground.

At nearly 7 inches across, ‘Aunt Shirley’offers an eyeful of color. This tall vividflower is named for the author’s sister,Shirley Welch.

July�August 1996 27

S O U R C E S 1

BAY VIE W GARDENS1201 Bay St., Santa Cruz, CA95060. Catalog, $1.50.

BOIS D ’ARCGARDENS 1831 Bull Run Rd.,Schriever, LA 70395; 504-446-2329. Catalog, $1.

CONTEMPOR ARYGARDENSBox 534, Blanchard, OK70310; 405-485-3302.Catalog, $1.

LONE STAR IRISGARDENS5637 Saddleback Rd.,Garland, TX 75043; 214-240-4016. Catalog, $2.

LOUISIANANURSERYRte. 7, Box 43, Opelousas,LA 70570; 318-948-3696.Catalog, $4.

REDBUD L ANE IRISGARDENRte. L, Box 141, Kansas, IL61933; 217-948-5478.Catalog, $1.

Texas to settle in a weekend cottage onsome old family property, near a lake. The grounds had never been “groomed,”were overgrown with cedars, wildflowersand weeds, and overrun with foxes andcoyotes, raccoons and armadillos, andsnakes—including copperheads and watermoccasins. If I planned to live here perma-nently, I had to civilize this place.

So I set to work making gardens, and soonit was decision-making time again: I couldeither go back to bearded irises, or I couldtry to grow the Louisianas in a climate thatwas hot and dry during summer, and coldin winter—very different from their naturalhabitat. Despite the scant encouragement Igot from other iris growers, I wasn’t goingto give up easily. By this time I had a con-suming interest in Louisianas, and wasgrowing them and promoting them to oth-er gardeners . I began interplanting a fewwith other irises—bearded varieties, spuria,Japanese and Siberian—and soon foundthat the Louisianas grew and bloomed justas well as the others.

As I continued civilizing my landscape,the biggest challenge was an old, aban-doned holding pond for minnows. Its edges were thick with weeds and grasses,seedling shrubs and native cedars. Passingfishermen had left trash behind, and a rockretaining wall along one side had crumbledinto the pond. I decided to clean up themess and turn the pond into a showcase formy Louisiana irises; I knew they wouldthrive in water.

Once cleaned and cleared, the pond wasabout 15 feet wide and 40 feet long. Whenit is full of water, the deepest part is about3 feet. Each end slopes up to ground level,where there are boglike beds. On the sideof the pond nearest the house, I built a nar-

row planting shelf. The irises planted onthe shelf and in the bogs gradually spread,moving toward the deeper water in such ahurry that their rhizomes actually grewover rocks. In fact, they multiply so rapidlythat I have to thin them a little very otheryear. And every four or five years, I have toremove almost everything and start over.

I’ve probably given away as many as 15,000rhizomes since starting the pond plantingin 1980. At bloom time, in late April andearly May, the pond becomes a riot of color.

A few water-loving plants have beenadded to extend the bloom season. Iris vir-

ginica and I. pseudacorus begin bloomingearlier than the Louisianas (photo, above).

28 Fine Gardening

Extend the season of bloom by planting different iris species together. Another water-loving iris, yellow flag (Iris pseudacorus ‘RoyDavidson’) blooms earlier than the Louisianairises, but its flowers linger long enough tocomplement a selection of bright Louisianas.

Japanese irises planted above water on thepond’s edge bloom about a month after theother irises have flowered, but their foliageforms a nice green background to theLouisiana iris blooms. Spider lilies, nativeto Louisiana and Texas, bloom with theLouisianas and require identical culture.Visually, there is nothing to compare with

the sea of flowers—whites and yellows andreds and pinks and lavenders and purplesand blues—blooming in and on the edge of the water. The irises, although growingmore than 400 miles from their nativehabitats, seem completely at home, and the pond has become a real showcase. It’s a treasure rescued from the trash.

My pond makes a pretty picture, and it isthe most photographed spot in my garden.People ask what’s in the pond, and I’mproud to tell them—after all, the Louisianasare now part of the family too. �

Marie Caillet has been growing Louisiana irises for

more than 50 years.

July�August 1996 29