My property is pretty much in the natural state, all woods, on the headwaters of the Nanticoke river. Our native Mountain Laurel are slowly dying, and developing dark spots on their leaves. These naturally grow on our property and are everywhere. Can you help me save them?
Sussex County Delaware
Judging from the photos, it appears that your mountain laurels have what is known as leaf spot, a fungal disease. There are several different fungal pathogens that can cause leaf spot. They may also still have damaged leaves from the winter. One of the causes of leaf spot is excessive moisture. We have certainly had a lot of heavy rain this spring. A couple of other things that can cause leaf spot are being too crowded (not enough air circulation) and not enough light (too shaded). Your laurels must be happy where they are or Mother Nature would not have allowed so many to grow there. It does appear to me that your laurels have new, healthy growth. That would indicate that they are not dying. I suggest that you pick off the diseased leaves and rake up any that you see on the ground.
Laurels can also suffer from botryosphaeria canker; another fungal disease. Fungal spores enter through wounds from pruning or other damaged areas on the plant. You would notice leaves curling and branches dying. Should you see this, remove the dying branches. I’m suggesting this because I can’t see the whole laurel.
Should your problem continue, please feel free to contact the Sussex County, DE Extension Office. The offices are closed right now due to Covid19, but someone is checking telephone messages.