|there is a light green moss growing on my walnut tree. is this something that can damage or kill t
|Answer from NGA
November 12, 2009
|I'm guessing it is a lichen which is not necessarily harmful to your tree unless it becomes very thick and holds moisture against the bark. If it holds too much moisture it can cause the bark to rot. You can kill off the lichen by spraying it with Bordeaux (lime sulfur) which is typically sprayed on apple trees during the dormant season (February). Spray directly on the lichen and eventually it will dry up and slough off (or you can peel it off). Best wishes with your walnut tree.
« Return to the Garden Knowledgebase Homepage