Without any idea of where you are located or any idea what variety of azalea this is, it's impossible to help. "Hardy azalea", means nothing unless we know In what temperature zones it's likely to survive outdoors.

I will tell you that even in my very mild climate, azalea 'trees' do not have a very long life expectancy unless in a very protected location. There is something about that bare expanse of trunk that makes them more vulnerable to cold than their typical shrubby cousins.