Most of the other hydrangeas should be pruned in summer, once they have finished blooming. Most of these bloom on what's called"old wood" - growth from the year before.
If you prune them in early spring, you risk cuting off the dormant flower buds. By pruning right after the blooms have faded, you allow the plant time to set buds for the next year. Sep 24, The climbing hydrangea should be pruned in summer after flowering. Prune smooth hydrangeas and paniculata species annually to a framework of branches to make them flower more prolifically.
Serrata can be treated the same as mophead and lacecap. Mophead and lacecap hydrangeas in a mixed garden shrubpruning.buzzted Reading Time: 5 mins. Jun 23, After the above varieties bloom, usually in June and July, it is time to prune. Avoid pruning after August 1, because the flower buds for next year’s blooms form in late summer.
To encourage branching and fullness, cut one or two of the oldest stems down to the shrubpruning.buzzted Reading Time: 3 mins.
It blooms on current season's growth, so prune it in late winter. Cutting it back to a foot tall produces fewer clusters, but they're huge (a trick I learned from Margaret Mosely in Decatur, Georgia).
Cutting it back more modestly produces many more, but smaller shrubpruning.buzzted Reading Time: 4 mins.