Well established endless summer hydrangea is progressively wilting. What’s happening?
Certified GKH Gardening Expert
It can be hard to determine what caused the wilt. I do have a question... Are those rocks placed on top of the soil that it is buried in, or are they planted just in the rocks? If they are not in actual soil, then it is likely drying out VERY fast. These will need quite a bit of water in regular soil, as they dry out. If they are only in rocks, then this might have to be irrigated constantly on dry days.
if this is properly in the soil, and only covered with rocks, then it could very well be a fungal infection. You can attempt to correct this with dolomitic lime and wettable sulfur.