Lace cap hydrangea
Is it to late to cut back hydrangea?
Certified GKH Gardening Expert
There are many varieties of hydrangea. Without knowing for sure which kind you have, it would be best to wait until after the blooming season is over to do pruning, other than deadheading or removing dead leaves and stems. If you prune now, you may not have any blossoms until next year.
Here are a couple of articles you might find helpful: