What is Lichen?

Lichen, found on tree trunks, homes, and rocks through the Lowcountry region, is a symbiotic relationship between fungus and algae. Lichen often looks like a greenish-gray, flaky substance growing on the trunk of a tree. The fungus and algae depend on surfaces with moisture in order to perform the photosynthesis needed to survive. There are about 13,500 species of lichen on the Earth!

The rhizines (similar to roots) allow the lichen to attach to the tree but do not go deep enough to harm the tree in any way. If your tree or shrub has lichen and is struggling, it is not due to the lichen. Lichen is not harmful to trees, themselves. If your plant is struggling and dealing with lichen, you will need to diagnose an underlying condition.