"David J Bockman" in
:

'Hardened off' refers to the leaves being sufficiently far along in
growth to survive frosts. Azalea blossoms (especially the white
bloomers, in my experience) are quite susceptible to freezes and will
turn to brown mush right at 31-32 degrees.





http://members.tripod.com/~John_A_Perkins/specsrcs.htm
(but, -10 F doesn't sound terribly hardy)

http://www.google.com/search?sourcei...azalea++usda+%
7C+zone



http://www.google.com/search?hl=en&l...dendron+usda+%
7C+zone&btnG=Search