Shrubs like hydrangeas flower from mid to late summer on the previous year's growth. Mophead and lacecap hydrangeas will bloom satisfactorily with little attention, but regular pruning encourages new, vigorous growth that can produce a better display. Likewise, other species, including the climbing hydrangea, will benefit from a trim. Such plants fall into RHS Plant Selector pruning group 4.
The pruning methods explained below are for individual types and species of hydrangea.
The most commonly grown hydrangeas in gardens are lacecaps and mopheads – mopheads are identified by their full, roundish heads of large petals; lacecaps have tiny flowers in the centre of the bloom and an outer border of large petals.