Encore

I have planted 2 encore azaleas in different spots. I have had them 3 or 4 years. One spot has no trees, so it gets all day sun and summer heat(Temps upto 100 at times), and the other has some shade but definitely sun on the edges. I got these because I read they were supposed to be bloom into fall, however both of them will only bloom for about 2 weeks or not at all. Does anyone have experience with these varieties, and can give input?