Hydrangea – Leaf Spot
Q: I planted two hydrangeas a year ago. The leave are now covered in round brown spots and they are not blooming. What should I do?
A: Hydrangeas commonly get a leaf disease called Cercospora leaf spot. It usually infects when leaves are regularly wet by rain or irrigation. It can also be a problem when the shrubs grow so densely that leaves can’t ever completely dry.
You can protect them by spraying with landscape fungicide (click for sources) when damage is first seen.