Aspen tree fungus

Asked August 9, 2017, 5:44 PM EDT

Hi. I have a couple of Aspen trees in my backyard in Bend, and they're not doing well. They're about 40 feet tall, but losing leaves and branches. The branches are covered with what looks like black fungus. Questions: 1) Can I do something to save these trees, or are they likely goners? 2) Is there a sub-species or type of Aspen tree less susceptible to this fungus that I can plant next time? Thanks, Jim

Deschutes County Oregon

3 Responses

Thanks for your aspen tree question. It's difficult to see exactly what is on your tree's limb(s), but what is more probably than a fungus is a lichen, which is a perfectly harmless symbiotic 'mix' of a fungus and an algae. They support each other, and just use your tree as a home, not as parasites, harming it.

It would be helpful to see photos of the entire tree, as well as the leaves and branches you believe are dying. Aspens are susceptible to several fungal diseases, but most of these are on the leaves, not the branches. Before you can make an informed decision about destroying this one and replacing it, the culprit needs to be identified, and we haven't gotten that far.

I'll try to help further with more information. Thanks!

Thank you for the additional pictures. I'm attaching a picture of an aspen leaf showing iron chlorosis. Can you compare it with some of the leaves on your tree? I'm also attaching a photo of an aspen leaf with leaf spot. Can you compare with others of the tree's leaves? I can't see the leaves close up or clearly, but, from a distance, some seem to exhibit one condition and others, another. Thank you!