|I live in central Florida and bought a heat resistant hydragena which has done very well until August when we got a lot of rain everyday, now it has black spots on all the leaves and I don't know what to do to combat it. The plant also does very well in full sun. If anyone has any information that can help me I would appreciate it.|
Those spots are a fungal disease or possibly a bacterial one. They usually don't threaten the life of a hydrangea but they do make it unsightly. You can purchase sprays for such things at your garden center to keep it in control. I find that in minor infections if I rake up fallen foliage and pick off affected foliage the problem often diminishes, provided the weather doesn't keep the plant wet for an extended period again. If you choose to spray do so right after rains to provide protection from infection.
Hope this helps.