Should hydrangea bushes be cut back in the fall? What about other perennials...
Thanks for the question.
Either way; the plants will do fine regardless.
Arguments for cutting back: less work to do in the spring, makes things look tidy, easier to apply a winter mulch (if you mulch), removes possible disease potential. Arguments for not cutting back: less work now, some plants catch snow and hold snow better, some plants have "winter interest", some plants provide cover or food for birds or animals, stems mark location of plants late to come up in the spring.
If you do cut back, wait until blooms are gone, and leave 2 or 3 inches of stem above the crown.