Question
I just have a few strange things growing on my crab apples and I’m not sure if it is harming them?
Joe, Garden Clinic Member.
Answer
It looks you have lichen on your tree but the amount growing is unlikely to cause any harm. For 95% of trees and shrubs, it is a sign of clean air, free of pollution. But for the other 5%, it can be just too much lichen smothering the bark. If required, carefully remove with a light brush, taking care not to scratch the delicate bark beneath.