Lichens survive in a very wide range of habitats worldwide. Amazingly, more than 400 species can be found in Maryland.

The presence of lichen or moss on backyard trees can understandably be concerning at first. Lichen is a combination of algae and fungus that lives on any number of solid, undisturbed surfaces, ...

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 ...