Japanese Flag Iris ensata

This is a perennial beardless iris native to Asia from Siberia to Japan in the herbaceous perennial Iridaceae family. Japanese Irises prefer a sunny site but tolerate partial shade. They are best grown on water edges in damp, rich, acidic soil with abundant moisture during the growing season. They can even withstand periods of standing water, but in the winter plants do not tolerate saturated soil or standing water. For best results, remove the plants from the water garden in the fall, or plant rhizomes in pots about halfway in damp ground and then remove to dryer ground for the fall and winter. Blooms appear in mid-summer after bearded and Siberian irises. They produce a flatter flower of 3 to 6 inches with a foreshortened standard of one to several blooms on a stem up to 4 feet tall. Cultivars can be single or double in a variety of colors with striking markings. The rhizomes reproduce to create an increasing mass and should be divided about every three years after flowering has finished. New rhizomes can be planted in the spring or fall at about 1 to 2 inches deep and, unlike other irises, should be planted vertically with the growing tip pointed up. Japanese Iris make a showy presence in the garden and are excellent cut flowers.

Insects, Diseases, and Other Plant Problems:  

More information on Iris.