Maybe I can get some advice here. Our hydrangeas have been great for several years. Early last year, all of the plants on one side of our porch never reached full growth, had yellower leaves and even dropped off a lot of them. Some of the stalks completely died. They are smaller and are recovering this year but are far behind the plants that showed no change. Here are a few pictures. First picture is a plant showing problems and the second is the very healthy plants. The issue has moved now to the "good" side of the porch but only in 1 plant. We have had amazing success with them since we planted them. Am I looking at some kind of disease here?