Bearded Iris — Tips for Care and Dividing

Newly planted iris will establish themselves well with regular watering their first year. Because they are shallow-growing, they don’t need too much soaking, and they are a good choice when water is scarce. The ideal time to plant is in the fall, so natural winter rains can help the rhizomes get a good start. These tips will ensure that your iris will thrive:

• An application of fertilizer in the spring will encourage them to bloom; however some varieties (or small, immature rhizomes) may not bloom until their second season.
• If necessary, protect leaves and flowers from snails and slugs with copper barriers or your preferred bait.
• Feed again after flowering is done in late summer or fall; this will help the rhizome gain strength as it ‚”rests” over the winter.
• Remove any dead matter regularly to discourage rot and bugs; this process happens all year but especially in winter. You can use household scissors to trim back leaves that develop brown tips.
• In late fall, cut leaves down to a few inches to encourage new growth. In cold climates, protect plants with layers of mulch.

Iris will spread happily into their available space, and after a few years you may notice that the rhizomes are lifting themselves out of the dirt, and are growing into a solid mass. If they become too crowded they will no longer be so happy, and will not bloom. That’s when they should be dug and divided.

Digging and Dividing Iris

Some experts say iris can be dug at any time they are not actively blooming, but fall or winter are the easiest, before mature leaves develop and when the ground is easy to work. Use a digging fork or (careful) shovel to lift the clump, starting from the outside edges and prying upward. A well-grown batch will be hard to lift!

In California and other warm areas, iris never go all the way into hibernation during winter. Try to dig and divide before new growth gets more than a few inches high.

Pull, break, or cut iris into individual rhizomes, with or without roots attached. Large, long pieces can be broken into two or more chunks (you will notice narrower places where a break would be natural). Remove any soft or rotten material and discard. If roots are very long, trim them to about 2 or 3 inches in length for manageability.

You can store dug rhizomes in a paper (not plastic!) bag, in a cool place, until ready to plant. One final note: Be sure that you never store or plant rhizomes, bulbs, or corms among your food plants—confusing an edible onion or potato with an ornamental bulb could result in serious illness.