Iris is a large genus of some 300 species from the Northern hemisphere. Irises are mostly rhizomatous or bulbous perennials grown for their flowers, which can be bearded, beardless, or crested. Some species also have variegated foliage. They are one of the best known and best loved garden plants.
Noteworthy CharacteristicsBeautiful blooms in many color combinations and forms. Excellent in many situations, including borders, beds, wet areas, and rock gardens.
CareEach iris group has specific cultural requirements. See individual species accounts for information.
PropagationSow seed in containers in a cold frame in autumn. Lift and divide clumps, or separate bulb offsets, and plant bearded irises within a few weeks in mid-summer. Plant beardless irises immediately after dividing in early autumn.
ProblemsIris borer, verbena bud moth, whiteflies, iris weevil, thrips, slugs, snails, aphids, and nematodes can cause problems. Bacterial leaf blight and soft rot, crown rot, rhizome rot, leaf spot, rust, viruses, and scorch can occur.