It requires regular moisture, especially up to bloom time, May to June, and will do very well beside a stream or a pond. Perhaps no other irises are influenced to as great a degree by culture as are the Japanese. Good culture will increase height, branching, flower size and quantity of bloom. They will grow and bloom better if planted in full sun in a heavy, rich soil with ample organic matter, especially manure or peat. The soil pH should be acid, ideally between 5.0 to 6.5. There is evidence that Japanese iris will tolerate a wider pH range, but growth and bloom will not be as good. Japanese iris are heavy feeders. A liberal application of a balanced fertilizer in spring and just before blooming is beneficial. 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 from 2004 until 2008 as part of our Aquatic Plants Program. 

The information about Iris ensata 'Chiyo no Haru' (Aquatic) 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.