My son-in-law has just moved and has an apple tree which has like a yellow fungus on it. Any ideas as to what it is and if it is worth trying to salvage?
Certified GKH Gardening Expert
The fungus is likely lichen or shelf toadstool. Neither are harmful to the tree but can indicate that the tree is suffering from something else. Does the tree look sickly otherwise? If not, then the tree will be fine. If it looks sickly, can you describe the symptoms and we will try to diagnose.