Are they in containers or in the ground? Azaleas like an acid soil, so if yours tends more toward the alkaline side, that would be a problem for the azaleas. The soil should have a pH of 5.5 to 6, I think, to make azaleas happy.
If the shrubs are in containers, it's much easier to control the pH of the soil, which is why I asked about that.
"Isn't it enough to see that a garden is beautiful without having to believe that there are fairies at the bottom of it too?" - Douglas Adams