Bearded iris is a traditional favorite plant for the perennial border. Get facts and information on growing and caring for bearded iris. They bloom in a rainbow of colors and bicolors that will brighten up any landscape. Use them next to your gazebo or favorite bench.
Bearded Iris Care
Bearded iris plants will grow in Zones 3-9 and will vary in sizes depending on the variety you choose. Sizes will range from 6-36”h x 12-24” h. They prefer full sun, or light afternoon shade in warmer climates, and fertile, well-drained soil.
Flower colors include shades of blue, purple, red, white, yellow, orange, and pink. Flowers have flashy standard (upright) petals, fall (drooping) petals, and beards. Beards are colored or white hairs in the center of the fall petals. Flowers appear in early spring to early summer. Shallow-rooted thick rhizomes produce fans of sword-shaped leaves. Bearded iris are classified into groups according to their size and bloom time.
The flowers may be grouped together according to bloom time and heights, much as you do tulips. Types include, miniature dwarf bearded, standard dwarf bearded, intermediate bearded, miniature tall bearded, border bearded, and tall bearded.
Plant them in odd numbered groups in the border or create an all-iris bed for the best effect. They make excellent cut flowers as they are spectacular and usually quite fragrant. Good companions include false indigo, delphinium, and ‘Butterfly Blue’ or ‘Pink Mist’ pincushion flower.
Depending on the cultivar, plant iris bulbs 12-24” apart in fall or early spring. Plant rhizomes horizontally 1” deep, with tops exposed. Apply slow-release low-nitrogen granular plant food at time of planting and each spring. Too much nitrogen will produce lush leaves but will reduce flowering. Add bonemeal to the soil at planting time for best results. Water deeply when the soil becomes dry. Add 3” vegetative mulch outside of the root zone and not over the rhizomes.
Propagation: Iris should be divided due to overcrowding or reduced vigor, usually every 3-4 years. Divide in mid to late summer. Dig around the rhizomes and lift (See steps for division). Cut back foliage to 6”. Reset healthy portions and discard pieces that are hollow, woody, soft, and ones that do not contain both healthy roots and top shoots. Plants often have reduced flowering the first season after division but flower freely the second season.
Pests and Diseases: Pests include iris borer, iris weevil, thrips, slugs, and leaf spot.
Dwarf bearded iris (Iris pumila) reaches 4-6” high, has gray-green leaves, and bears purple, blue, or yellow flowers in spring.
Japanese iris ( I. ensata) reaches 36” high and bears flowers with reduced standards in shades of purple and reddish purple in early summer. The leaves have a pronounced midrib.
Louisiana iris (I. fulva) reaches 18-36” high and bears nonbearded bright red to rust and occasionally yellow flowers in early summer. It prefers moist soil and hot summers. It may spread fast, but is suited for southern heat.