Iris japonica has been growing outdoors for me here in zone 7A/B in central
Virginia for about 7 years and has spread around the garden in shady areas.
It puts out long runners and can move about 3 ft. in a year. The foliage
is knocked back in the hardest winters, but the rhizomes seem to survive
and come back. It has only bloomed once, a single stalk three years ago,
but it is a spectacularly beautiful iris. I also grow I. confusa (perhaps
my plant is a white japonica??) as a house plant, but it blooms only if
regularly transplanted and gets crowded in pots quickly. There is also a
very pretty variegated Iris japonica that seems as hardy here as the plain
form. It makes a nice ground cover in shade and might bloom if it got more
sun and enjoyed a mild winter. Paradoxically the supposedly hardier I.
gracilipes has never lasted more than a year here but it seems the hot
summers might be the problem.
PS--the variegated "Iris tectorum" offered by Van Bourgondien Bros.
appears from its photograph to be I. japonica, but they also illustrate an
offer of Spanish Iris (bulbous forms similar to Dutch Iris) with a picture
of a regeliocyclus hybrid! Is there a variegated tectorum, does anyone
Best wishes, Bill
William A. Shear
Department of Biology
Hampden-Sydney VA 23943 USA
phone (804) 223-6172
FAX (804) 223-6374