Failure to bloom

You're watching oakleaf hydrangea buds swell in spring but no flowers appear, or they're sparse. This is typically poor siting, too much shade, extreme cold exposure, or improper pruning of old growth in the wrong season. Choose morning sun with afternoon shade, avoid frost-prone pockets, and prune only in late winter before buds break. Remove up to a third of the oldest canes to improve flowering.

Cultural management is your first line: remove infected material, clean up debris, and improve the growing environment to make conditions less favorable for the pathogen. Avoid wounding plants during maintenance, as many pathogens enter through fresh cuts. Chemical options are available for severe cases, but they work best as preventive treatments applied before symptoms appear.