EASY CARE TIPS FOR YOUR MOONROCK® HYDRANGEA v WATER Give your plants a good soaking about once per week, and more often when it’s hot. Keep in mind that plants in containers dry out faster than in the ground. If leaves are wilting or curling, more water is needed. Use a soaked hose or drip system to make watering easier. hy PRUNE In spring, after the threat of frost is over, trim to about 18 inches (45cm) tall to encourage healthy branching and flowering that season.