Knowledgebase
Lilac leaves browning and shriveling #877750
Asked July 18, 2024, 10:00 AM EDT
Anoka County Minnesota
Expert Response
Hi Mike,
Your first photo looks like powdery mildew. See this page, and follow the links for recommendations on what to do:
https://apps.extension.umn.edu/garden/diagnose/plant/deciduous/lilac/leavesblotches.html
You'll see information on bacterial blight right below the mildew information.
Good luck.