Diagnose: Rhododendron Bud Blast

1. Tiny black bristles support true fungal bud blast
2. Look closely at several brown unopened flower buds. A hard bud that stays attached and develops many tiny black pin-like bristles strongly supports bud blast caused by Seifertia azaleae. A smooth brown or black bud after a freeze points more strongly to cold injury, especially when the exposed side of the shrub is worst. Soft water-soaked tissue or gray fuzzy growth after prolonged wet weather fits Botrytis, while a narrow pointed bud may simply be a vegetative bud rather than a failed flower.

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