QuestionsHow to growTrees and ShrubsTypes and Usesyellow moss on trees 0 Vote Up Vote Down Alan Stenson asked 16 years ago Is the yellow moss which grows on tree trunks and branches bad for trees? should it be removed or sprayed? 1 Answers 0 Vote Up Vote Down Gerry Daly Staff answered 7 years ago Moss and lichens on trees are no harm to the tree, a thing of beauty in themselves, and should be left intact.