Did you mean to include a picture of the black spots? There are several causes but most likely a leaf blight or fungal infection is causing the spots. Or the spots could be sun damage or herbicide spray. I suggest you remove the damaged leaves and do good fall cleanup in case it is a blight disease. Fallen leaves can help overwinter the disease so remove all leaves in the fall. In the spring your hydrangea will have a fresh start. Try to avoid overhead watering as this encourages leaf blights. Keep growing, Marianne Binetti