Moving a bearded iris is a relatively common garden task for many reasons. These easy-to-grow plants multiply quickly and often outgrow their space. Many growers transplant irises in order to spread their favorites around the yard or share them with a friend. Sometimes gardeners realize they planted an iris in the wrong spot to begin with. No matter what the reason, learning how to move a bearded iris correctly will help it thrive in its new home.
Identify a new spot for your bearded iris. It should be located in a well-drained area that receives at least a half-day of sunlight. Make sure the space is large enough that it allows the iris plenty of room to spread.
Prepare the new bed. Dig up the soil and work in plenty of organic matter. Add a low nitrogen fertilizer to help give the plant a strong start
Wait for the right time. The ideal time to move an iris plant is during their dormant period in summer, about six weeks after blooming. This will give the plant time to establish roots in its new bed before the growing season ends.
Dig up the iris. Using a garden spade or shovel, dig around the entire plant. Include as much of the root mass as possible. Carefully lift the plant by the base of the root mass with a garden fork or by hand.
Divide the plant as needed. Dividing bearded iris plants every 3 years or so encourages blooming. Unless the plant is very young, divide it now to avoid digging it up again soon. Find the narrow place where the original rhizome---the plant's thick, fleshy root---is joined with younger rhizomes that have sprouted to the side. Using a sharp knife, cut the new rhizomes away from the old original. Discard the old central rhizome.
Trim the leaves and roots. Using a sharp scissors or garden shears, cut the leaves back to about 6 inches. Trim any damaged roots.
Dig a shallow hole for each plant in the new bed. The holes should be about 6 inches wide or big enough to accommodate the rhizome. Leave a mound in the center of each hole.
Place the rhizome into the hole on the center mound. Spread the roots down around the mound. The rhizome should sit higher than the rest of the spreading roots.
Bury the roots. Firmly cover the roots while leaving the top of the rhizome slightly exposed or barely covered with a thin layer of soil. Press the soil down firmly to ensure good contact with roots.
Water thoroughly. Water the relocated plant regularly until it becomes established.