Commentary: The magnificent perennial named iris
FARGO — Old names have certainly circled back into popularity, and according to recent lists, garden-related names are back in style, too, like Violet, Dahlia, Ivy, Lily, Rose and Daisy. I guess no one wants to name their baby Chrysanthemum.
I was surprised, however, that Iris didn't make the list of baby names. I've met some fine Irises over the years, both human and botanical.
Perennial iris is well-named after the Greek goddess of the rainbow, and few perennials can match the wide-ranging assortment of colors, including white, yellow, blue, purple, lavender, orange, rust, brown, black and near-red. They are truly the orchids of the flower garden.
Iris belongs to a group of perennials that form the sturdy backbone of any perennial garden, joining others like peony, daylily, bleeding heart, hosta, tall phlox and lily. Even after an iris' flowers have faded, the blue-green, sword-shaped leaves add an elegant foliage contrast.
There are different types of iris, from the early flowering dwarfs through the mid-summer species, but the iris most familiar is the bearded, or German, iris, Iris germanica. "Bearded" refers to the bushy beards on each of the three downward facing petal-like sepals called "falls." The true petals are called "standards," the upright part of the iris flower.
Bearded irises bloom in late May through June, depending on the variety and the season's temperatures. Seeing an iris in full bloom reminds us to acquire some or add more.
Traditional iris planting time is August, which is the best time to dig, divide and replant established iris beds. But thanks to the invention of the plastic nursery pot, iris plants are available from many garden centers throughout the growing season and can be successfully planted spring through August.
Besides potted plants, bare-root divisions are often sold in August by retailers and mail-order companies.
Irises grow from thick, underground stems called rhizomes that are sometimes mistakenly called "bulbs." Leaves grow in a fan shape from the top of the rhizome, and the fibrous roots grow below.
When planting an iris, depth is very important, as the rhizome mustn't be planted too deeply. Whether planting potted iris or bare-root divisions, the rhizome should be just barely covered.
Remember, the actual roots that require soil contact are below the rhizome. It's preferred if the rhizome is slightly visible at soil level after planting, especially in heavy clay. If planted too deeply, flowering is hindered and rhizomes can rot.
Irises flower best if planted in full sun, or at least six hours of direct sunshine. They resent "wet feet" and will easily rot in too-wet spots. An easy way to ensure good drainage is to rake soil into a small mound for iris groupings. Amend heavy soil with peat moss or compost.
Irises are most dramatic planted in groups, such as three of the same color planted about 15 inches apart in a circle.
How often should iris be dug and divided? On the average, clumps should be dug every three to four years in August, separated into healthy rhizomes, each with a fan of leaves, and replanted.
Looking for an iris that rarely needs division? Siberian iris, with its narrow, sword-like leaves, grows in a tall, circular clump, tolerates moist soil, rarely needs division and adds a bold feature to the perennial garden.
Don Kinzler, a lifelong gardener, worked as an NDSU Extension horticulturist and owned Kinzler's Greenhouse in Fargo. Readers can reach him at forumgrowingtogether//growingtogether.areavoices.com.