Have a crimson maple tree with leaves covered in a white residue top and bottom. Is it possible that this is white powdery mildew? If so, how do you treat an entire tree? If not, what else could it be? The tree is approximately 50 years old and is in full sun.
Crimson Maple Tree Problem
Certified GKH Gardening Expert
Yes, this sounds like powdery mildew. Neem oil is oftentimes effective. Here is more information: https://www.gardeningknowhow.com/plant-problems/disease/powdery-mildew-homemade-and-organic-remedies.htm