Plant Obsessions: SIBERIAN IRISES

I have to confess to being an Iris nut. They've all got gorgeous, colorful, and elegant flowers, and a few are even scented. There's an Iris for any situation in any garden, and if only they'd bloom from March through October, have gorgeous fall color and handsome winter silhouettes, they'd be perfection itself. In my garden, Siberians rule (though I'm working on obtaining a prodigious number of Pacific Coast cultivars as well).

My first memory of seeing one is from many years ago, when I picked up the White Flower Farm catalog and was bowled over by the rich purple beauty of 'Ruffled Velvet'. The descriptions of the others being offered were, if anything, even more tempting. I succumbed and ordered the sampler of 6, unable to bear the thought of waiting another minute to own such opulence. And I've never been disappointed, adding new cultivars regularly to a growing variety of sites and combinations around the garden.

Siberians have slender, upright deep green leaves, generally growing about 3-3 1/2' tall but ranging from 2-4', with flowers ranging from 3" wide in the species to 6" in newer cultivars and with 3-5 flowers opening sequentially on a stem. I have one variety, 'Nana Alba', which is 6" tall with white flowers not significantly smaller than some of its taller cousins.

The flowers are generally held right above the tops of the leaves or slightly higher, so that one sees the whole plant at once rather than having flowers making a separate show as in bearded Irises. This gives an impression of mass and substance that continues even after the flowers fade. They bloom May through June; by judicious selection of cultivars, you can have about a 6-week bloom period throughout the garden.

One thing that attracts me to Siberians is the richness of the colors; many varieties are shades of saturated blues and purples, although 'Cambridge' is an attractive light blue. Handsome wine-red shades exist in plants like 'Chilled Wine' and 'Eric the Red', and there are excellent whites as well as cream and soft yellows and a few smoky pinks. One of my favorites is 'Sea Shadows', a complex blend of blues and turquoise that is both unusual and stunning. A host of blue shades anchor my 80' red bed color scheme; wines and reddish purples wander through my magenta and silver garden; whites and 'Pink Haze' consort with soft pink roses; and 'Butter and Sugar' and 'Dreaming Yellow' are a central part of my cool soft yellow and lavender-blue Oasis garden.

The clumps of small rhizomes spread outward from the center, slowly adding girth each year. After 4-6 years, the center of the clump has died out and the plant is forming a ring of foliage; this is the time to divide it, although you can divide sooner if you want to increase your stock more quickly. The important thing to remember when dividing is to leave a reasonably generous number of rhizomes per division, as small divisions of 1-2 rhizomes may struggle or fail to survive. More is better in the case of Sib divisions.

Plants are easily divided between foliage fans with a sharp kick on a thin-bladed square point shovel or spade. I have always divided and reset plants in the fall, although authorities differ as to whether spring or fall is more appropriate. The books say that if you divide in fall, you definitely won't get bloom the next year since they settle in slowly. This is also my experience. You'll get a few blooms the second year, and they really start to settle in and bloom well the 3rd. One book says that if you divide in early spring you may get bloom that year.

One of the things I like best about Siberians is their toughness. In my garden, fending off weeds and living through drought are necessities, and Siberians take it all in stride. I can grow them anywhere I've got full sun or a bit of shade. Even though they prefer very moist soil, a good top dressing of compost annually, and a well prepared site initially, for me they've tolerated every kind of adversity, and bloomed through it. I wouldn't be without them.

Sources: Chehalem Gardens in Newberg, Joy Creek Nursery in Scappoose, Caprice Farm in Sherwood, Northwest Garden Nursery in Eugene, Hedgerows in McMinnville are the locals-- Chehalem has by far the most. The catalog from Willowood, in Parkdale, lists a goodly number. Expect to pay $3-5 for bareroot divisions, or $7-10 in gallons. Marilyn Dube at Natural Design Plants in Portland also has them. She's been an SHPS vendor in the past - I got 'Lady Vanessa' from her at the first sale, in a 4" pot. I've even gotten them at Fred Meyer, and I'm sure garden centers will have them, but probably not the named varieties-- more likely seedlings (which is what I got at Freddy's).