Aspen black spot on leaves - Ask Extension
I have a couple of aspen trees with black spots on the leaves. I’m wondering what might cause this and what to do about it.
Thank you.
Knowledgebase
Aspen black spot on leaves #872645
Asked June 11, 2024, 2:48 PM EDT
I have a couple of aspen trees with black spots on the leaves. I’m wondering what might cause this and what to do about it.
Thank you.
Summit County Colorado
Expert Response
Hi Sue,
That looks like it is being caused by aphids. If you look in the black are of the leaves, you should see some tiny, oval shaped green insects. Here is a close up photo of what they look like: Aphids on aspen leaf. They mostly cause aesthetic damage but can cause some small branch die back in the long-term if they are a persistent issue. There are many natural enemies of aphids which typically keep their population in check. This article explains treatment options for aphids: https://extension.colostate.edu/topic-areas/insects/aphids-on-shade-trees-and-ornamentals-5-511/
Thank you for using AskExtension!
- Denyse
That looks like it is being caused by aphids. If you look in the black are of the leaves, you should see some tiny, oval shaped green insects. Here is a close up photo of what they look like: Aphids on aspen leaf. They mostly cause aesthetic damage but can cause some small branch die back in the long-term if they are a persistent issue. There are many natural enemies of aphids which typically keep their population in check. This article explains treatment options for aphids: https://extension.colostate.edu/topic-areas/insects/aphids-on-shade-trees-and-ornamentals-5-511/
Thank you for using AskExtension!
- Denyse
