Question
I live in NC and have two weeping willow trees that are about 2 years old.  They have been doing great but the leaves now have brown spots and are turning yellow and falling off.  I do not believe the spots are caused by bugs and the trees gets plenty of water.  What can this be?

Answer
Hi Brooks, Many fungi cause leaf spots but are not serious enough to warrant preventive sprays. Rake up the fallen diseased leaves in the fall.

Powdery mildew causes a white coating on the leaves. The disease is usually not serious.

Rust causes yellow spots on the lower surfaces of leaves and, if severe, defoliation. Rake up and destroy leaves from diseased trees.

Tar spot causes black, raised spots on leaves. The spots are harmless. Rake up and dispose of fallen leaves from diseased trees at the end of the growing season.

One of these should help with your problem.  kathy