My mountain laurel shrubs have developed brown spots on the leaves. These appeared almost overnight after some recent heavy rains. No sign of insects or mold. Any suggestions? Thanks in advance for your help.
Mountain Laurel Shrubs
Certified GKH Gardening Expert
Various leaf spot fungi cause yellow, brown or black dead blotches on mountain laurel leaves. These blotches frequently run together, causing heavily infected leaves to turn yellow or brown and fall prematurely. Cool, moist weather encourages these diseases, especially when new leaves are developing. Shake out all fallen and diseased leaves from the center of each laurel shrub and destroy them. Remove all dead branches in the center of individual plants or hedges to allow better aeration. Mulching helps prevent the disease from splashing up from the ground and infecting plants. Spray at weekly to 10-day intervals with sulfur or copper fungicide, particularly in rainy weather. Dig up and discard seriously infected shrubs together with the root system and soil ball.