Giant gray leaves

Asked August 11, 2020, 10:00 AM EDT

I'm wondering whether my photos are clear enough for you to be able to see the giant gray leaves, growing among the lilac bushes. I look out this window every day, and just noticed them! Unlike any lilac I've known. Pam

Hennepin County Minnesota

1 Response

I can’t be sure without a close up the leaves but it is probably powdery mildew. It is common on lilacs and promoted by hot and humid weather. Treatment usually isn’t required. Sanitation and increasing air flow by pruning just after it flowers is beneficial.