Y'know, I think they're hardy to at least zone 8 although the database says 9b. I've seen them in gardens in Vancouver BC, but the one I'm thinking of is on the south side of my friends' house. Their climate is moderated by proximity to the sea, but they do get snow and some temps below freezing most winters. That being said, in Feb. 2010 when the Olympics were in Vancouver, it was colder here than it was there . . .
Here they grow under the tree canopy of the live oaks, which all by itself does give some protection. Mine's pretty big, obviously been there a good many years, and wasn't bothered by the two cold winters we had in '09 and '10.
