Hi! I was interested in growing a protea outside, and wanted to know which would be able to survive the (USDA zone 7a) climate here.

Hello Cephalotus90,

I'm in no way an expert in Protea, but to my best knowledge, no species from the genus Protea, and I think no genus from the familly Proteacea (but this second assertion should be verified) can withstand, say, 20°F. So below USDA zone 8(b), I'd say forget about it, especially in unsheltered zone 7, even 7b.
Sorry to be negative. However if I prove to be wrong, I'd like to know more about hardy genus from that wonderful familly.
Rajesh.

Thanks for answering! I have done a little research, and I believe I have found a few that are hardy enough. It seems that both Protea dracomontana (Drakensberg Sugarbush) and subvestita (Waterlily Sugarbush), along with both Grevillea victoriae (Royal Grevillea) and juniperina (Juniper Grevillea), and Embothrium coccineum 'Lanceolatum' (Chilean Fire Bush) should be able to bear the winter. I'm still trying to find out more information; anything will help!