fungal leaf spots on Hydrangea
Quick answer
If your Hydrangea has fungal leaf spots, the most likely cause is: Fungal leaf spots (such as Cercospora or Corynespora cassiicola) thrive in humid, warm conditions when foliage remains wet for extended periods. They typically start on lower leaves as small brown or purple spots and spread upward.
Start here:
- 1. Remove and dispose of heavily infected leaves (do not compost them).
- 2. Avoid overhead watering; always water at the base of the plant to keep leaves dry.
Why Hydrangea gets fungal leaf spots
Fungal leaf spots (such as Cercospora or Corynespora cassiicola) thrive in humid, warm conditions when foliage remains wet for extended periods. They typically start on lower leaves as small brown or purple spots and spread upward.
How to reverse fungal leaf spots on Hydrangea
- 1
Remove and dispose of heavily infected leaves (do not compost them).
- 2
Avoid overhead watering; always water at the base of the plant to keep leaves dry.
- 3
Apply a copper-based fungicide or Neem oil early in the season to prevent the spread, though it will not cure already spotted leaves.
Keep fungal leaf spots off this Hydrangea
Space plants adequately to ensure good air circulation. Clean up fallen leaves and debris around the base in late fall, as the fungus overwinters in dead plant material.