While some gardeners enjoy the challenge of planting flowers that take a lot of care, others prefer selections that are easier to grow, but just as beautiful.

The various colors of iris, along with their delicate petals are appealing to gardeners looking for something that’s not quite as hands on as some other plants can be, which makes them a great choice for more relaxed gardeners. 

Irises are hardy perennials and live a long time. They feature graceful flowers that form the backbone of many gardens. When well cared for, irises need to be divided every three to four years. Crowded iris will begin to decline growth and have fewer and smaller flowers. Another sign the iris need to be transplanted is if the rhizomes start heaving out of the ground. Overcrowded iris rhizomes will start to push against each other, which results in the entire root system pushing right out of the ground. If the iris roots look like a big pile of spaghetti, it’s time to divide and conquer.

Now through the end of August is the prime time in Oklahoma to divide and replant your iris. To begin, lift the clump of iris plants out of the ground with a spade or garden fork. Go ahead and throw away parts that may be diseased, riddled with insects or those that are small and weak. 

Next, separate the rhizomes into segments with one fan of leaves and several roots. Cut the leaves back to about 6 inches. This will allow the plant to more easily re-establish its roots without having to support a large amount of foliage at the same time.

The iris can be replanted once the iris rhizomes have been divided. When planting the new plant, spread the roots out in the soil and position the top of the rhizome at the soil surface. Be careful not to plant too deep as they won’t flower well and are more susceptible to disease and insect attack. If you’re planting several irises near each other, point the rhizomes away from each other and space the new plantings about 18 inches apart.

Spread out the roots around the rhizome and then cover the roots and rhizome with soil. You’ll need to thoroughly water in the newly transplanted plants. Now the irises are ready for the fall and winter season and should produce more flowers next year.

David Hillock is a consumer horticulturist with OSU cooperative extension.

Recommended for you