oak trees dropping sap

Asked July 17, 2017, 1:06 PM EDT

Hello! We have many oak trees dropping sap and prematurely dropping green acorns. Its a mess! Can you tell us what is going on and what to do?

Dakota County Minnesota oaks horticulture sap dripping

1 Response

Some years oaks have a natural drop of small green acorns. That usually seems to happen after we have had a mild winter and more acorns were produced than needed. What you have dropping is probably honeydew from aphids. They are especially active this year. They really are not going to harm your tree and natural enemies should soon find them. Here is a link: https://www.extension.umn.edu/garden/insects/find/aphids-on-deciduous-trees-and-shrubs/