Donald, thanks. Eh, I guess I will lift that pot and bring it in. We're definitely going into the 20s, and did once, which is when it took damage. It isn't completely dead yet (leaves at the base looked okay) but clearly not doing wonderfully like the other three I have out there.
I think our database ought to be modified to reflect this. I'd call this a zone 8 hardy plant, but not a zone 7.
Too bad! It's so lovely when it spreads among rocks....
