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Mystery fungus on apple tree #930224

Asked April 30, 2026, 11:26 PM EDT

I have this super old beautiful apple tree in my backyard, and it seems to be growing a mold/moss on it. I want to know if it will harm the tree or anything mostly, but also would like to know what the name of the fungus is and if it has any other implications.

Benton County Oregon

Expert Response

Thanks for contacting ask extension with your question about the white fungus on your apple tree.  From the picture it looks like you have a fungus that feeds on dead wood.  If that's the case, then there is not much you can do since it's on the main trunk.  

I recommend you evaluate your tree as a structural safety issue. Consider removing it or contact a licensed arborist to evaluate the tree if there is a chance it could hit a house, playground, power line, etc. 

To get a positive ID on the fugus you can contact the Oregon Mycological Society (https://www.wildmushrooms.org)

Here is a publication which  has pictures of different kinds of wood decay fungus. https://ipm.ucanr.edu/home-and-landscape/wood-decay-fungi-in-landscape-trees/?src=302-www&fr=4363&tpl=HLS01%5CTemplates%5CHLS_302Redirect_1_2022.cfm#gsc.tab=0

Hope this helps, sorry about the tree. 

Deb K Replied May 01, 2026, 9:20 PM EDT

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