I like to keep the flowers on through the winter and deadhead in early spring. Some hydrangeas bloom on old wood, others on new. The reblooming hydrangeas flower on both old and new wood. In early spring, careful to just snip off the old flower, I avoid cutting off the flower buds that formed the previous summer. For more pruning details, the Endless Summer website has helpful information on pruning and overwintering hydrangeas.
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