Iris (Iris germanica), also known as Bearded or German Iris, has more than 100 varieties to choose from and grows best in USDA hardiness zones 3 through 10. This perennial garden favorite flower can grow anywhere from 8 inches to 4 feet tall with colorful flowers blooming from late spring into fall, all depending on the variety of flower. Iris flowers are grown from rhizomes or woody roots that multiply quickly each season, making it a favorite plant to share with family and friends. They make beautiful cut flowers and are often seen in bridal arrangements. Requiring only minimal care, you can grow irises in your own garden for years of enjoyment.
Plant irises in sunny locations that receive minimal shade. Too much shade reduces the amount of flowering. The soil needs to be well draining, and amending with compost before planting can help if you have heavy, clay soil.
Water consistently two to three times weekly as needed to keep the soil moist. Using a soaker hose or garden hose with water running at a trickle works best.
Trim dead foliage and leaves as needed to keep the flowers tidy. Cut off dead flowers immediately to encourage more growth and blooming. When the flowers stop blooming and begin to fade in the fall, cut the stalks back to the base of the plant.
Apply a thick layer of mulch over the base of the plants when the ground freezes. Use a 4- to 5-inch layer of either shredded bark, chopped leaves or pine needles. The mulch protects the iris rhizome or root from heaving or coming up out of the ground as it freezes, thaws and refreezes.
Divide iris rhizomes every four to five years to produce new plants. Dig up in late fall about four to six weeks after the flowers are done blooming. Gently pull the rhizome apart and replant the pieces. If not planting right away, shake off excess dirt and store in a paper bag in a cool, dark and dry location such as a garage or basement.