Last fall, we transplanted four azalea bushed from the front of our house to the back. They are right next to each other in a row. Now that sprinf has arrived, I find that one of the bushes is fine, but the leaves on other three have become really brown. I had watered them extensively after transplanting. Is this browning more likely a disease condition or lack of water. (I haven't watered them in the last two months). thanks.......