Hydrangea Disease

Question

Both of my hydrangeas have a disease, big black spots on the leaves. They were fine until a week ago. Can you tell me what this is and what I can do to make the hydrangeas healthy once again?

Answer 1

It could be either black spot or sooty mold. Both are treatable and, in most cases, not fatal to the plants. These articles will help:
(this is about black spot on roses, but it applies to all plants) https://www.gardeningknowhow.com/ornamental/flowers/roses/black-spot-roses.htm
https://www.gardeningknowhow.com/plant-problems/disease/how-to-get-rid-of-sooty-mold.htm