Q. I notice many of my pine trees have lots of bright green-gray things growing on the trunks. Is it a virus? What is this? Is it harming my trees? What can I do to reduce or eliminate it? A. I am ...

Those green-blue growths that you see on tree trunks and branches are not mosses. They are lichens. Lichens are not killing your tree, nor are they causing it to fail. They are telling you something ...

Now that deciduous trees are bare, trunks and branches have taken center stage, and you might be noticing nuances and irregularities that evaded your attention over the summer. For instance, what are ...

Oak wilt is a fungal disease that kills oak trees, spreading through the roots of the interconnected trees. We are about to enter the prime susceptibility time of year (Feb. 1 through June 30), so ...

Algae, lichens and moss often form green or grey, powdery or mossy, crusty growths on the stems, branches and trunks of trees and shrubs. Pictured here, lichen and moss. This dreary "gray all day" ...