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?

I know many of us want winter to come to an end, but I would like just one more good snowstorm. I love all seasons, but I need a little more of that winter bleakness in the woods, primarily to help me ...

Over the course of many years working with trees, hundreds of people have asked me about “that stuff” growing on the bark, or hanging from the branches of trees. What is it? Is it a disease? Is it ...

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 ...

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 ...

Gardeners and homeowners often contact our Horticulture Hotline at Cornell Cooperative Extension in Oriskany when they notice a grayish blue-green crusty or mossy looking growth on trees, shrubs, ...