Bud blight in rhododendrons

Q: The flower buds on my rhododendrons dry up and turn black before they bloom—any ideas why this would happen and what I can do? The trees appear to be healthy and produce many buds, but very few make it to the flower.

I inherited these plants when we purchased an older home; the garden is very mature and I would guess the trees are 15 years old.

“Bud blight” (Briosia azaleae) can be evident on flower buds that turn brown and dry up in spring. These buds never open. Upon on closer inspection, one can see black bristles covering the flower bud surface, which indicates these presence of this fungus. Sometimes an entire bush could lose all of its current’s spring bud.

There is no recommended chemical spray. Remove all infected buds and dispose of them in the garbage. Do not compost infected buds. Maintain an ideal growing environment by mulching plants, deep watering, fertilize as instructed on the package, and adequate air circulation.