That old question arises every spring. I even ask myself, “Now, when should I prune my hydrangeas?” I think I have finally figured it out for the ones in our garden, but there is no single answer. The right time of year to prune your hydrangeas is a tricky proposition. Pruning time depends on the species, and if you don’t know the species, you can ruin your flower display for the season. Some species of hydrangea bloom on old wood, and some on new wood. To confuse the issue, remontant or reblooming hydrangeas are bred to bloom on both old and new wood.
Hydrangeas that bloom on old wood should be pruned in June or July after flowering. If you prune them in the spring, you will cut off the buds that are waiting to bloom. Hydrangeas that bloom on new wood should be pruned in late winter before new spring growth appears.
Remove dead, damaged, or diseased branches at any time of year, cutting them to the ground. You can also remove branches that cross or rub together and those that stick ou...