Saw the great blue mounds at Kew Gardens last year. But most kinds aren't hardy here in New England. There are a few types that are listed pretty much everywhere as hardy. One is a native North American with white flowers, and the other is a hybrid called Marie Simon with pink flowers. But most of the blue ones are listed as hardy anywhere from zone 6 to zone 9 (for the same species or hybrid!), depending on which web site you visit. So I thought I'd ask here if anyone has them growing, because after all the plants can't go online to see where they are supposed to grow! :-)