It performs best in sun or partial shade in a rich, moist, acid soil. Do not use lime or other pH raising materials around Japanese Iris. Cut the plants back to a height of 6 inches in the fall. Japanese Iris are useful near water and can be divided every 3-4 years as plants become crowded. Replant the rhizomes about 2 inches deep and 18 inches apart. This Iris is happy in shallow standing water and cannot tolerate hot, dry conditions. Cold hardy to 10-15° F.

Iris ensata is grows in the wet land throughout the Japanese archipelago. The genus Iris gets its name from the Greek goddess Iris, who was goddess of the rainbow. In Greek mythology, Hera, who was Queen of Olympia, was impressed by Iris' purity and honored her with a flower that bloomed with all of the colors in her robe. The specific epithet is from the Latin word 'ensatus' meaning "sword" in reference to the shape of the leaves. We grew this plant when we were growing many other aquatic plants from 2004 until 2012 as part of our Aquatic Plants Program. 

The information about Iris ensata 'Blue' displayed on this web page is based on our research conducted in the nursery's horticultural library and from reliable online resources. We also include observations made about it as it grows in our nursery gardens and other gardens we have visited, as well how the crops have performed in containers in our nursery field. We will also incorporate comments we receive from others and welcome hearing from anyone with additional information, particularly if they can share cultural information that would aid others in growing this plant.