Iris versicolor or Blue Flag, is a native of Eastern Canada and the northern United States found in swamps and in lowlands. It grows 2-3 foot with 1-inch sword-shaped leaves. The rhizomes are the commercial source of Iridin.
Blooming Time: May-July. The blue flowers with yellow and white markings are 3-4 inches across.
Culture: Iris versicolor need full sun to partial shade with a heavy, rich moist soil. We use a soil mix consisting of 2 parts clay to 1 part loam to 1 part sand. The plants are kept moist at all times, which makes it a great plant for water features. The plant should be fertilized in the spring before flowering and again after the blooms have faded. They grow very quickly and should be re-potted on a yearly basis.
Propagation: Iris versicolor are propagated by division or by seed. Seeds need a 3-month cold, moist stratification. The seed should germinate in 21-60 days at 60° F.
Iris versicolor was featured as Plant of the Week December 14-20, 2001.
Guide to Past Plants-of-the-Week:
Cal's Plant of the Week was provided as a service by the University of Oklahoma Department of Microbiology & Plant Biology and specifically the late Cal Lemke, who used to be OU's botany greenhouse grower and an avid gardener at home as well. If the above links don't work, then try the overview site. You may also like to look at the thumbnail index. ©1998-2012 All rights reserved.