Nate I am in Tallahassee Florida where even a "dry" summer is wet compared to your conditions generally so Crinum flaccidum hybrids including Bradley don't go full dormant for me in the summer but they do slow down and stop producing new foliage especially when mid summer is intense and drier. During the peak of drought Bradley has lost all the foliage but always the neck remains, so you should have the marker you are looking for. Alani Davis Tallahassee, Fl