Japanese iris ( iris ensata) are a showy iris that is surprisingly hardy (zone 3) if planted in the right location. They need rich damp soil and a spot that gets at least six hours of sun a day. For best blooming, feed them every spring with rooted manure or other organic fertilizer. The soil should be friable so that it can easily retain moisture.
The iris clump will gradually increase in size over time, but it is not nearly as robust as Siberian iris that will produce a large patch with lots of blooms in a short time.
This one is a frilly double that looks quite different from the purple one. They also come in shades of pink.