Fungus on apple tree

Asked May 17, 2016, 9:40 PM EDT

A fungus on one of our apple trees has almost killed it - but whats's worse, it looks like its neighbor, another apple tree, is developing the same problem I think it's too late for the first tree but I hope to save the second. I'm attaching pictures of the first, more diseased tree. Can you tell me what I can do to try to save the second tree (and first if possible). Thank you! Cheryl

Washington County Minnesota

1 Response

Thank you for the question. There might be lichen on your trees. Lichen live on water, light, and materials from the air on healthy trees, as well as stressed or otherwise unhealthy ones and can trouble homeowners. Lichens rarely have anything to do with poor top growth or death of shrubs and trees. Instead their appearance is often related to damage from environmental stress or poor management. Exposed limbs on damaged plants simply give lichens access to the sun they need for growth with little competition. As best we can tell from the photos, your trees look quite mature. Mature tree bark changes and can create more beneficial environments for the lichen to grab onto. If your trees are starting to decline from age or other reasons, more light, water and air flow will move through the branches providing ideal environment for the lichen to thrive. Read more here to learn more about lichen:

You may wish to have a certified arborist come out and take a look at your trees to see why the lichen are thriving.

Thank you for contacting Extension.