Lichen on tree bark
What do I do about Lichen on tree bark?
Certified GKH Gardening Expert
Unless you just don't like looking at them, you don't have to do anything. These do not harm the tree in any way. They occur quite frequently on many tree species. Here is an article for more information on this subject: https://www.gardeningknowhow.com/ornamental/fungus-lichen/treatment-tree-lichen.htm