American Basswood leaf spots - Ask Extension
Just noticed these colorful, non-brown spots on the American Basswood tree in my backyard yesterday. Rest of the tree shows no signs of distress nor a...
Knowledgebase
American Basswood leaf spots #871268
Asked June 03, 2024, 10:42 AM EDT
Just noticed these colorful, non-brown spots on the American Basswood tree in my backyard yesterday. Rest of the tree shows no signs of distress nor any apparent rot. Hydration appears appropriate, other leaves are very green with new growth at the crown, and prior spotted lantern fly infestation from last year does not appear to be affecting the tree’s overall health.
However, we need assistance in identifying proper management for the spots. Not certain if they are a precursor to brown spots which will destroy the leaves and photosynthesis, or if it Is larvel attachment of another type?
Baltimore County Maryland
Expert Response
This looks like a type of leaf gall which can be common on Tilia species. A common cause is from a eriophyid mite that rarely requires treatment and when on a large tree it can be difficult to spray the entire canopy.
If the tree is otherwise healthy it should be fine. Heavily infected leaves will eventually fall off and you can either let them be or rake up and dispose of them. It won't necessarily prevent it from happening again.
You can monitor for any changes and the galls may eventually elongate or remain pimple like in appearance. If you notice other signs of concern, feel free to send additional photos.
More from Ohio State University on Leaf Galls.
Emily
