All irises are popular border plants. The range of colors for bearded irises approximates that of a rainbow.
Irises prefer full sun but tolerate light shade. The soil should be of average fertility, moist and well drained. Bearded iris tolerates dryer soils and should not be overwatered. Yellow flag prefers very moist soil and can even be grown in standing water.
Divide in late summer or early fall depending on the species. Only replant clean, disease- and insect-free rhizomes. Deadhead irises to keep them tidy.
Use irises in borders. Yellow and blue flag irises are also useful alongside streams or ponds. Dwarf cultivars make attractive additions to rock gardens.
Wash your hands after handling irises because they can cause severe internal irritation if ingested.
Many iris species and hybrids are available. Among the most popular is the bearded iris, often a hybrid of I. germanica. It has the widest range of flower colors. I. cristata (dwarf crested iris) is a low-growing, native species that bears multi-colored flowers. I. fulva (copper iris) bears copper blooms. I. orientalis (Spuria iris) is reliable and offers vanilla-scented blooms. I. pallida (Dalmatican bearded iris) bears amethyst blooms in April. I. pseudoacorus (yellow flag, Louisiana iris) is a water dweller and tolerates wet locations where little else thrives. I. sibirica (Siberian iris) offers assorted cultivars with flowers in a variety of shades, including purple, blue and white. I. versicolor (blue flag) produces blooms in shades of light to dark violet-blue, but cultivars are available in shades of red, pink and reddish purple.
Features: spring, summer and sometimes fall flowers in almost every color combination including bicolored and multi-colored; attractive foliage
Hardiness: zones 3–10
Notes: Ask for remontant (reblooming) iris cultivars for flowers in spring and again in fall.