Question
purchased pretty about 12" high in pot, should I plant now in garden or leave till autumn or spring, also is this variety winter hardy?

Answer
Mary,

The sooner you get the plant into the ground, the faster it will be able to establish a strong root system. All Azaleas show the same amount of winter hardiness. To be safe, I would recommend treating it with an anti-dessicant in the late fall to protect it over the winter.

Good luck,
Ed Gulliksen