Japanese Iris is a beardless iris of real presence, native to wetland edges from Siberia to Japan, and one of the showiest of the entire genus. Where bearded irises produce upright, ruffled standards, Iris ensata opens something flatter and wider, its three to six inches of flower face spread almost horizontally, giving it a quality that is more lily pad than flag. Cultivars range from pure white to deep violet with elaborate patterning, and they carry themselves on stems reaching up to four feet in mid-summer, a season when the garden can use all the drama it can get.

Growing Japanese Iris well means understanding its relationship with water. During the growing season it wants abundant moisture, even tolerating shallow standing water, but once autumn arrives it resents wet roots. The practical solution is to grow rhizomes in submerged pots that can be lifted to drier ground in fall. It thrives in acidic, rich soil and blooms for years with minimal intervention, though clumps benefit from division every three years. Plant new rhizomes vertically with the growing tip pointing up, set just one to two inches deep, and this species will reward with an expanding colony that fills the waterside beautifully.