I bought a rhododendron approx 2 months ago. It was doing fine for about a fortnight forming buds. It then went downhill. It now looks like its dying. At start leaves and plant started to go brown plus the buds never opened within the two months. I have watered it thoroughly to no avail. I then gave it an examination and have noticed the buds are going a greyish colour.Could the root of my problems have been Rhododendron Bud Blast?