Hello, Wyngate. Can I ask you some questions? Are pictures 1 and 3 the same? Do you have any additional pictures of leaves with large browning areas as opposed to small brown spots? I am trying to see what these areas look like and where within the plant those large brown lesions are.
I assume you water with a sprinkler system? How often do you water and about how many gallons of water does it get?
If you insert a finger into the soil at a depth of 3-4", does the soil feel dry, damp or wet? What type of soil do you have where that hydrangea is?
From when until when does the plant receive direct sun?
Thanks in advance, Luis