Add beautiful flowers to your garden!

Bearded irises are grown from a thick fleshy root called a “rhizome”. The rhizome feels like a tough potato in texture. These rhizomes should be planted in the ground during the fall months to give the roots time to become established before winter. When you buy a new iris, you will probably receive a rhizome with clipped roots and leaves. It can remain out of the ground for a week or two without serious harm, but the sooner it is planted, the better.

Plant your bearded iris in a sunny (6-8 hours) location with well-drained soil planted with the top of the rhizomes at the soil or up to an inch below the surface of the ground. Read Three Myths About Bearded Irises for more information on planting.

Bearded irises do best with a low-nitrogen fertilizer, apply once in early spring and once after blooming.

In about 2 or 3 years, a decrease in blooms usually indicates that it is time to divide your plants. Be sure to divide the plant by cutting the newer parts of the rhizome free from the old section and discard the older part.

When you receive your beardless rhizome, it will be wrapped in damp paper and placed in a plastic bag. Immediately remove the rhizomes and soak the roots in water overnight. These roots do not like to dry out so plant immediately in the fall, about four weeks before the first hard freeze. Beardless rhizomes like to be planted 1″ below the soil (2″ below for the Japanese Iris).

Though beardless irises are often called “water irises”, most varieties do great in the garden. They enjoy a full to partial sun location and a balanced fertilizer in the spring when the plants are a few inches high. Japanese Irises are especially heavy feeders and appreciate a second feeding of fertilizer before bloom time. During dry periods, mulch the roots to help retain moisture.

Beardless irises can grow for several years in the same location. Japanese irises are the exception – they like to be divided every three years.

Easy to grow Dutch Irises are grown from a bulb (not a rhizome). The bulbs can be planted in both fall and spring. Plant the bulbs about 5″ deep with the pointy tip-up.

These Iris are a popular flower used by florists in seasonal flower designs. They flower in late spring to early summer and can be grown in sun or partial shade. The bulbs are hardy from Zone 3 – 9.

Dutch Irises look best when planted in groups. For a stunning show, plant about a dozen bulbs per square foot.

National Garden Bureau recognizes and thanks The American Iris Society as author and contributor to this Year of the Iris fact sheet.

This fact sheet is provided as an educational service of the National Garden Bureau. There are limitations on the use but please credit National Garden Bureau when using all or parts of this article or referencing the Year of the program.

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