Thanks for the comments, everyone. I have been trying A. blanda on top of a sand dune with open shade under conifers, where it persists for 2-3 years, then disappears. We actually have quite dry summers here, so I'm not sure that summer wet is the problem, but winter wet might well be the issue. Roger is correct in noting that we get more than 85 inches of rain per year, though it falls mostly from October to April, with less than a half inch per month, usually, from May to September. I am always willing to try killing off another species, so may look into A. appenina. Curiously, I grew Scilla peruviana outside here for years without problems. Then two very wet cool winters in a row, this year and last, and it was gone. Kathleen