Nathan I have several Alstomeria in my home garden in the hills of El Cerrito, and of course, we have huge patches at UCBG where it got down to 24F; it has been colder in the past. No damage to any that I can tell. Paul Paul Licht, Director University of California Botanical Garden 200 Centennial Drive Berkeley, CA 94720 (510)-643-8999 http://botanicalgarden.berkeley.edu/