DARREL KOEHLER: The Prairie Gardener — The Colorful Iris

The name for the beloved iris is very fitting. In Greek mythology, Iris was the goddess of the rainbow. This is one perennial flower that comes in just about every color in the rainbow. No other flower can make that claim.

The iris family is large. There are 11 different divisions of iris from the noble bearded to Siberian and water iris. They are found in the Northern Hemisphere.

The plants of each division are slightly different from those of any other. Compared to orchids in France, each flower manages to convey its beauty in a unique way.

Irises grow from either rhizomes, which are underground stems, or round onion-shaped stems called bulbs.

Beginning gardeners are especially fond of irises. These hardy herbaceous perennials need little care or attention. There are so many varieties of iris that you can have a season of bloom, including even “repeaters,” which bloom not once but twice yearly, in spring and fall.

Bearded irises are the most familiar. Also known as the German iris, no perennial garden would be complete without them as they come in a vast array of colors, heights and flower forms. They are generally hardy from Zone 3 through 7.

It is a good idea to cover newly planted irises the first winter so they can take the future winters in stride. This spring, irises didn’t put on a flower show we normally expect. Lack of snow was blamed for much of the flower damage. The previous winter was much cooler, but damage was less due to abundant snow cover.

Irises have simple needs. They require full sun and good drainage. Soil should be not too rich. They do better in moderate fertility. Irises should not be crowded by other plants. And keep irises free of weeds by practicing clean, shallow cultivation.

Bearded irises can be divided or planted almost any time. Late July or August are perfect times to divide old plants. Dig up and then use a sharp knife. Remove any rot or soft portions of the rhizomes.

Bearded irises are great for beds, borders and foundation plantings. The divisions you plant should be a single, current-season rhizome with a single fan of leaves. Cut the leaves back to 6 to 9 inches to help ease planting stress. They should be planted in a shallow hole — like a duck on water.

Plant four to six single divisions 12 to 15 inches apart to form a group. Space groups about 4 feet apart.

Irises really can grow, and in normal conditions, you may have to divide every three or four years. Siberian Spuria irises can be added to your bed for variety.

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