When this tree (9 feet tall) goes dormant, does it lose all its leaves? I have been battling yellow dropping leaves since I got it at a yard sale. It is in my sunniest room and I think it was outside. I'm sure it is stressed, as I took it home in my car. I don't see bugs, but I did use a bug spray on it. Should I try Dawn dishwashing soap? It is still flowering but dropping leaves like crazy.
Hydrangea usually don't perform well indoors for more than a couple of weeks. When they go dormant in winter, they lose all the leaves. Even in "Florida Rooms", hydrangea are unhappy. The trip home in a car had nothing to do with yellowing leaves...it's lack of light. Eventho hydrangea are shade loving plants, there is a huge differences in outdoor shade and indoor bright light. If possible get the plant into a location that provides morning sun and afternoon shade.