Dear All, I have a clump of C. x powellii which is now about 3 ft across and which has weathered about five winters here in Zone 6. But more noteworthy is the C. cv 'Carolina Beauty' which I got from Brent and Becky? It has not bloomed yet, after 5 yrs, but it has survived through all sorts of abuse including last winter when it got down to a "fearsome" 7F. As Jim Waddick suggests, deep planting is one of the ingredients for success. Dell -- Dell Sherk, SE PA US Zone 6. Amaryllids, South Americans, Cyrtanthus, Hardy bulbs, succulents and cactus, gesneriads.