When I bought potted azalea in December, I was told not to transplant in this season. Azalea basically starts blooming in spring. Maybe this grew under the temperature control.
I've failed growing azalea some years ago. Summer in Yokohama might be too hot and humid to them.
It can't grow in too hot summer and it doesn't grow in too cold season.
Wrote on Jan. 12 2004.