Gardening Tips and Highlights Waushara County Master Gardeners

Planting and caring for your Irises

The tall, beautiful Iris, named after the Greek goddess who rode rainbows, comes in many magical colors. Every gardener wants this perennial. Despite its divine origins, it is hardy, reliable, and easy to grow. They also attract butterflies, hummingbirds, and make lovely cut flowers.

There are some 300 species in the genus Iris. The most familiar irises are the tall bearded irises (Iris germanica). Irises need at least half a day of sun and well-drained soil, without enough sun, they won’t bloom. You should plant irises in mid to late summer. They have rhizomes (fleshy roots) that should be partially exposed or thinly covered with soil. Plant rhizomes singly or in groups of three with the fans outermost, one to two feet apart, depending on the size.

Dig a shallow hole 10 inches in diameter and four inches deep. Make a ridge of soil down the middle and place the rhizome on the ridge, spreading roots down both sides. Fill the hole with soil and firm it gently. You should water your Iris thoroughly and top-dress it with a low-nitrogen fertilizer. Don’t trim iris leaves after they have finished blooming. Leaves carry on photosynthesis for next year’s growth.

After two to five years, clumps become congested or lose vitality and stop blooming, this is the time to divide. Dig up the clump, shake off the excess soil, and use a sharp knife to slice away individual rhizomes. Keep only the ones that are firm, dry, and have roots and a fan of leaves attached. At transplanting, cut foliage back to two to three inches in length. This will allow the rhizomes to properly re-establish themselves in their new location.

Irises are deer-resistant and drought tolerant; however, they are susceptible to borers, so check the rhizomes yearly for holes and discard any infested ones.

The iris is the French standard “fleur-de-lis” and also the symbol of Florence, Italy. Oral root, taken from the dried roots of Iris “Florentia” was considered a cure for blood and lung diseases, and teething babies were encouraged to gnaw on a “finger” of dried root for its natural fluoride. Information for this article was obtained from The Old Farmer’s Almanac. Check out website: