Pruning hydrangeas is crucial for maintaining their health and enhancing flower production. April is particularly suitable for pruning mophead and lacecap varieties. According to the Royal Horticultural Society (RHS), these hydrangeas bloom on the previous year's growth, so careful pruning can lead to more vigorous growth and a better flowering display. For mophead hydrangeas, gardeners should remove faded flowerheads and trim stems back to the first healthy pair of buds. Lacecap hydrangeas can be pruned after flowering to prevent energy loss from seed development. For mature plants, removing one or two of the oldest stems can stimulate fresh growth. However, if extensive renovation is needed, cutting all stems at the base will remove flowers for that summer, with new blooms appearing the following year. Climbing hydrangeas require pruning only after their summer flowering, and excessive cutting should be avoided to maintain blooming for the next couple of years.