What Causes Brown/black Spots On My Hydrangea Leaves?

This may sound like a contradictory answer, it could be too much or too little water.  The inconsistency of watering could well produce brown spots.  They can also form if the leaves get wet and then the sun comes out and the water droplet acts like a magnifying glass and attracts the sun which scorches the leaves in circles.

Sounds to me like they have mites on them. You will need to spray them in the shade with Garden Safe insecticide soap. It works, but keep them away from you other flowers if you can. They spread fast.

I have hydrangea and i'm having problems with black spots, what ca i us t ge rid of this fug us