When is the best time to prune my Bigleaf hydrangea?

You should not prune your Bigleaf hydrangea at all for the first couple of years after planting it, until it become well established, except to remove dead or damaged stems. Once it is mature, you may choose to cut it back annually depending on the type of growth you like. Flower buds are formed on the new growth produced each spring, sometimes called “new wood.” To ensure that there is plenty of new wood each season, many gardeners choose to do a hard pruning around the end of winter to early spring. Many people also like to deadhead (pruning off dead flowers) throughout the summer and into autumn as flowers die off. That is a right action because it keeps the plant looking tidy and also allows it to divert all its energy into other parts that are still actively growing.