Answer: That orange growth is lichen, not a rust pathogen. Lichen do not harm the tree or shrub in any way. They tend to grow only on that outer bark and stay there, not growing deeper into live ...

Lichen grow harmlessly on tree trunks and no control is needed. In fact, presence of lichens on healthy trees should be welcomed as likely positive indicators of lower levels of air pollution and a ...

This photo shows a lichen growing on hickory tree bark. Folks sometimes become concerned when they notice strange gray-green patches on the trunk or branches of a tree. Should the growths be removed?

Once upon a time, my street used to be loaded with towering, shade-providing tall trees. It was a gorgeous tree-lined street, similar to the reputable Tree City USA award-winning streets throughout ...

Q: I am worried about the grayish-green, flaky, roundish spots I am seeing on big tree trunks and branches this spring. I can scratch it off with my fingernails. I think that it is killing my trees.

Q. My 20-something-old redbud tree has developed lichens on the trunk, which is a first. Do I have a problem and is there anything I should do? I have another one in the yard which doesn’t have this ...