Weeping cherry tree
The lichen is not causing any harm to the weeping cherry. No treatment is necessary.
Lichens often appear as a perennial green or gray coating on the trunks and branches of trees. They are actually two organisms in one, being composed of a fungal body harboring green or blue-green algae, which live together in complete harmony. In the symbiotic relationship, the algae, through photosynthesis, supply carbohydrate food to the fungus and in turn, receive protection and trapped water and mineral elements from the fungus. In this relationship, the algae and the fungus are not distinguishable except with a microscope, and the lichen persists longer than the algae or the fungus would separately. You can call 270-685-8480 for more information at the Daviess County Cooperative Extension Service Office.