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 ...

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 ...

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 ...

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" ...