Q: Why do the leaf's on my pussy willow have yellowish brown spots on them?
Spots on willow leaves usually point to a fungal disease. There are several that attack willows. I suggest you take a branch to your local independent garden center for a visual ID and recommendation for a fungicide labeled for willows. Do clean up any leaves that fall and dispose of them in the trash to reduce re-infection. This is not a silver bullet and reapplication is usually require at 7 to 10 day intervals as directed on the label. Best And Happy Yardening, Nancy.