I am located in metro Atlanta and have found D. rotundifolia impossible to grow. I got plants descended from a population in massachussets (assuming they were more heat-tolerant than the pacific northwest-derived plants). In fear of them growing during the fairly mild Georgia winter, I overwintered the plants in the freezer and planted them in the bog garden in late March. The plants broke dormancy literally within 3 days. The plants had full rosettes in two weeks and were flowering in 1 month. Unfortunately, the plants shrunk and died by early June. I think that If I could get plants descended from New Jersey or Southern Japan, I would be more sucessful. There is a natural population about 2hrs north of where I live, however, plants descended from the Georgia mountain population are virtually nonexistant in nursery trade. Has anyone had luck with D. rotundifolia in a climate with hot summers?