When is the best time to prune hydrangeas

Question

When do I prune hydrangeas?

Answer 1

This article will help you:
https://www.gardeningknowhow.com/ornamental/shrubs/hydrangea/prune-hydrangea-bushes-hydrangea-pruning-instructions.htm

Answer 2

Right after they bloom! (and that applies to all types of blooming hydrangeas)
Any later will decrease or even prevent next year's blooms.