Iris flowers are popular plants, having been portrayed in paintings by Van Gogh and Georgia O'Keefe. In Greek, the word "iris" means rainbow, and in Greek mythology the goddess of the rainbow is known as Iris. Iris flowers are also mentioned in works by well-known poets, including Robert Frost.
Bearded irises are hardy perennials that require little maintenance, and there are thousands of varieties to choose from. They are characterized by six-petaled flowers. Three petals are upright and three hang downward with a fuzzy "beard" running down the center of each fall. Blooms appear in spring in a range of colors including yellow, blue and multicolored. Some newer cultivars have fragrant flowers that appear in spring and then again in the summer or fall. Types of irises vary in height from less than 8 inches to 38 inches. Plant them in summer through early fall to allow them to become established before winter weather arrives. Place mulch over irises that have been planted in fall to protect them over winter. Some varieties of irises are drought tolerant, but most prefer soil that is moist but not overly wet. Fertilizer is not usually necessary if the plant has healthy, green foliage. Irises that bloom in spring and then re-bloom in summer or fall should be fertilized in the spring as new growth appears, and then again when spring flowering has finished. Divide bearded irises every 3 to 5 years.
Japanese irises, as their name entails, hail from Japan and several surrounding countries. These are beardless irises that bloom after the tall varieties of bearded irises. They produce large, flat, ruffled blooms that may be either single or double. These irises prefer moist, loamy soil and at least 6 hours a day of full sun. Mulch around them with compost to keep the soil healthy. Japanese irises are heavy feeders, so fertilize them each spring and then again before they bloom. At the end of the growing season, cut the leaves off at ground level. Be sure to discard the leaves, as they could be contaminated with disease and pests. Replant Japanese irises every 3 to 4 years.
Dwarf Crested Iris
Dwarf crested irises grow as wildflowers in many areas of the United States. These small flowers grow to be 4 to 16 inches tall with bunches of pointed leaves and flowers. The blooms are purple, blue or white and marked with a characteristic stripe of yellow or white. They may appear singly or as couples on short stalks. Plant them in moist, well-drained soil in a shady location. Dwarf crested irises attract hummingbirds.