by Marilyn Pokorney
The beautiful Iris is a very easy plant to grow.
There are two basic kinds of Iris; Bearded and plain. There are also miniatures that grow only eight inches tall as compared to the traditional Iris which grows up to about three feet tall.
The Iris is a perennial plant that grows from a root called a rhizome. Plant them about 12 inches apart. The rhizome should be planted even with the soil with the top of the
rhizome above ground.
Plant Irises in full sun or partial shade. Iris needs well drained soil. Root rot can result if they are planted in soil that stays too wet. They tolerate drought very well, needing water only during the driest part of the summer. Fertilize lightly about 6 weeks before bloom time.
Plant in July, August, or September. For southern states October and November are not too late. The plants need to be well established to get through the winter.
Mulching is a matter of preference. A little mulch will help keep down weeds but the rhizomes need sunshine so do not mulch very deeply.
Divide Iris every 3 to 4 years or when they stop
producing as many blooms which is a signal that they need more space. Dig up and plant only the newest part of the rhizome tossing the older parts into the compost pile. When transplanting be sure each rhizome has some root and at
least a couple of leaves.
Irises aren’t bothered by many insects. The root borer is the major pest of iris. It is a caterpillar that chews on the rhizomes and causes the rhizome to rot. Thrips can cause damage to the buds but can be easily controlled by spraying insecticidal soap or by dusting the buds with diatomaceous earth.
At the end of blooming time the stems should be cut off but the leaves should be left to grow the rest of the summer. The leaves are making food for the rhizome so the plant can flower again next season. Any leaves that have brown spots or look unhealthy should be removed.
More Iris Resources
American Iris Society
Database of registered Iris varieties.
About the Iris Conjuration and its Ancestors
Illustrates the Iris family tree.
Species Iris Group of North America
Studies the wild species of the genus Iris and related irids.