Knowledgebase
Lilac hedges #878590
Asked July 24, 2024, 2:03 PM EDT
Hennepin County Minnesota
Expert Response
Thank you for reaching out to ask2.extension.
Unfortunately there is not much you can do. This is a lilac blight and it spreads through wind and rain, both of which we’ve had lots.
They can be treated with a copper based fungicide, but that needs to be done in the spring. If you want to do that search for lilac blight, you should find suggested products to use. I can’t recommend anything specific.
Depending on how big and how old your lilacs are, they could be cut back to get rid of the infected branches. If the shrubs are old, they may struggle.
whatever you decide, be sure to clean up and get rid of all debris that falls on the ground. The blight can overwinter in the ground debris.
