It produces large, fluffy flower plumes in June through July. Plants grow 6 to 8 feet tall. Its large size makes it unsuitable for small gardens. Venusta' is a widely grown variety with deep pink flowers. The large, flat flowers may be up to 10 inches wide.
Numerous cultivars are available.
Flower colors include white to blue, purple, reddish purple, and lavender-pink. The flowers often have veins, stripes, or blotches of a contrasting color. Japanese iris requires moist, acid soils. It grows in partial to full sun. Compared to bearded iris, Japanese iris has few insect or disease problems.