- Garden care: Hydrangeas do not like to dry out. In dry weather, soak the roots with a hose and the plant will usually recover. Remove faded flowerheads in spring after the danger of frosts, cutting back the flowered stems to a strong pair of buds. Take out misplaced or diseased shoots. Mulch young plants with a well-rotted manure or compost in spring. Once established, remove a quarter to a third of the shoots to the base of the plant.