when to prune hydrangeas on standards
Pruning Mophead, Lacecap, and Oakleaf Hydrangeas. Method I. Prune these hydrangeas only in the summer before August (to be safe). Some experts believe these hydrangeas may be pruned even into August, but this might be risky. The hydrangeas may already have set their bloom buds for the next year. Method I is for hydrangea types that bloom on old wood.