Answer: Hydrangeas do not need much routine pruning, but if you need to control the size or the plant has become thick and overgrown at the center, you can do that type of pruning right after it blooms. Each spring, you will also need to remove any winter killed stems. Be cautious in doing this and wait until late spring to be sure they are truly dead. The reason to wait is that these plants bloom on old wood that grew the year before, so pruning in fall, winter or spring will remove flowering wood for the summer. In your area you will likely have to do so much spring pruning due to winter damage that you will rarely need to do any thinning or size control. I hope this answers your question.
Q&A Library Searching Tips