Should I worry about lichen on an oak tree?

Answer by  plantman1979 (72)

Lichen are harmless organisms that grow on the surface of trees and rocks. They pose no threat to the health of your tree.

Answer by  georgesmith (138)

Lichen is not a problem on an oak tree. It is an interesting organism which does not harm the tree like a fungus would. The lichen is just using your tree like it would use a rock, as a support structure.

Answer by  paulab (7)

Lichens are the result of a symbiosis between an algae and a fungi. The lichen needs sunlight, 'cause it is able to produce their own food and they don't need anything from the tree and they will not enjury the tree.