My hydrangea leaves have dark spots on them. What do I do?
Hydrangea Leaves Have Dark Spots on Them
Certified GKH Gardening Expert
It could be either black spot or another fungus. This article will help with black spot: (it referes to black spot on roses, but it applies to all plants) https://www.gardeningknowhow.com/ornamental/flowers/roses/black-spot-roses.htm
If you don't think black spot is the problem, treat the plant with a fungicide.