Growing to love iris: Choose your favorite colors and styles to plant this summer or fall - Garden: Outdoor Living

Sunset, May, 2002 by Jim McCausland

* This is the season when the tall bearded iris reveals why it has won the hearts of so many admirers across the West. These nearly foolproof plants mix well with other perennials, grow in every Western climate, and multiply in the garden without becoming invasive. Chances are you probably don't live too far from a world-class iris grower, from whom you can choose your favorite varieties and order rhizomes to plant this summer for bloom next spring in your own garden.

A century of intensive breeding, much of it by amateurs, has transformed these irises from supporting players into the divas of the garden. Every season, growers flood the market with new varieties. One major grower told us that he replaces 50 or 60 of the 300 varieties of irises in his catalog every year. In such a fast-changing scene, how do you find the right iris? Start by looking at the past winners of the Dykes Memorial Medal, which has honored the best-looking and best-performing irises since 1927. The Dykes winners tend to stay around longer than more faddish varieties.

Price can also help you decide. A new introduction might sell for $50 per rhizome, but by the end of its commercial life span (5 to 10 years), the same rhizome will cost just $4 or $5.

Breeders perform magic

COLOR. You can buy irises in every color except true rose red and lime green (there are pale chartreuse wannabes). Banded and bicolor types abound, but much current breeding is focused on color variegation--stripes and speckles, as in 'Batik' and 'Bewilderbeast'--which is gaining acceptance faster among serious gardeners than among iris show judges.

If you want to grow irises to view up-close, choose banded, bicolor, striped, and speckled kinds. But if you want to mass irises for concentrated color viewed across the garden, get solid colors. FORM. Originally most bearded irises had droopy falls (the petals that hang down). But as breeders have pumped more substance into them, the falls have flared out (some are nearly horizontal). The amount of flair and ruffling along petal edges is a matter of taste.

BEARDS. Resembling fuzzy caterpillars, beards are centered on the falls. Early on, growers spent a lot of time breeding beards with complementary or contrasting colors, but now they're selecting varieties with elongated beards shaped like spoons, horns, and flounces. FRAGRANCE. The first time you sniff an iris that smells like grape ('Wild Thing' is one), you'll be enchanted. The scents vary in character and intensity.

BUD COUNT. Each flower lasts two or three days, so more buds translate into longer bloom. The most prolific irises produce more than a dozen buds per stem. The danger here is that spring rains can weigh down the flowers, so when strong winds follow, they can knock flower-laden stems to the ground unless they're staked. If you don't want the hassle of staking tall plants, choose intermediate or dwarf bearded irises, which tend to bloom earlier and stand up to the elements better.

LEAVES. A few irises, like 'Honky Tonk Blues', have a beautiful oxblood flush at the base of the leaves; someday, you may see whole leaves with that color.

Planting tips

Iris rhizomes (swollen underground stems resembling tubers) produce the fans of leaves that give rise to the flowers. Plant rhizomes so all the fans are parallel, and, if your garden layout allows, face them toward full sun.

Plant from July through fall in mild-summer climates; wait until October in Southwest deserts. Irises need fast-draining soil to avoid soft rot. Set rhizomes barely below the soil surface; in hot-summer gardens, cover them with about 1/2 inch of soil.

Irrigate from the time fans start growing in early spring until about six weeks after bloom. During summer, the rhizomes of most irises should be allowed to go somewhat dry In hot climates, water about once a week if soil is light and about every other week if it's heavy; in cool climates, water half that much. However, continue watering remontant (reblooming) types as long they're actively growing.

Scatter a complete fertilizer over iris beds when growth starts in spring and again after the last flower fades.

How to use iris

Although bearded irises combine well with many other perennials, some gardeners put them at the back of the border, so that when the irises finish blooming, they'll disappear among the other plants. Other gardeners prefer to interplant them with spring flowers such as columbines, daisies, dianthus, Iceland poppies, lupines, and peonies.

RELATED ARTICLE: Some growers welcome guests

The growers whose physical addresses appear below welcome visitors during iris bloom. Others are strictly mail-order sources for rhizomes. Call or check websites for catalogs and ordering information.

ARIZONA Shepard Iris Garden. Open for bloom 9 to-5 daily in April. 3342 W. Orangewood Ave., Phoenix; (602) 841-1231. Catalog $1.

CALIFORNIA Greenwood Irises Daylilies. Open 9:30 to 4 on Saturdays, April through June. 8000 Balcom Canyon Rd., Somis; (562) 494-8944 or www.greenwoodgarden.com. Catalog online.