Hydrangeas Not Flowering?

Hello !

It could be due to the way you pruned them. Pruning an hydrangea is not easy. It has to be done at the end of the winter season. You should first cut the dead flowers but just above the new bud, that is the important point, because the flowers appears on the old wood only, that is the part of the branches which are already one or two years old. This is to make the hydrangea produce flowers, and to keep a nice shape and help the growth of new shoots you have to first cut the dead branches (they are blackened) and some of the oldest branches, to recognize the oldest branches is easy they are whiter, stronger and branched.

You have to cut right to the foot, because you want more space and light for the new shoots.