Hydrangeas: To Prune or Not to Prune? and When Exactly?

Written by Greenwise Team
Published on November 21, 2018
We love hydrangeas in our area, so chances are pretty good that a hydrangea of one species or another is blooming in your garden. What makes hydrangeas so popular is their beauty—those big, beautiful white, blue, pink, and dusty pink blooms–and easy maintenance.
ANNABELLE HYDRANGEA (AKA SMOOTH HYDRANGEA) IS A NEW-GROWTH SHRUB Sometimes, however, it’s confusing as to when (or even if) you should prune your hydrangea shrub. The timing depends on whether it’s old growth or new growth. Fall is the perfect time for pruning your new growth hydrangeas. Wondering what a new growth hydrangea is? New Growth vs Old Growth Hydrangeas There are two main categories of hydrangeas – those that bloom on new wood and those that bloom on old wood.  New wood means flower buds are established on new branches that are generated this season. Old wood refers to when flower buds are generated from old branches from past years. All hydrangeas benefit from deadheading, which is simply removing the spent flowers.  You don’t have to do this immediately after flowering – many of the flowers persist through the cold, dreary winter and add interest to an otherwise empty landscape.  Instead, you can make it a part of your spring clean-up routine. Whatever you do – don’t worry!  These shrubs are resilient and will survive if you prune them at the wrong time of year.  You may have fewer flowers for one season, but after a full cycle, they should be back and blooming for you! One note of caution, after a hard prune (or an abnormal winter) your blooms could lose their vibrancy for a season as the plant recovers.
  • Endless Summer Hydrangeas
  • Twist and Shout Hydrangeas
  • Oakleaf Hydrangeas
These varieties bloom on older branches and don’t require pruning other than to maintain their shape and size.  Ideally, you want to do any significant pruning after the flowers finish, but before they set the new buds for next year. Usually, this means finishing your pruning by early August. If the shrubs are losing vigor and not producing flowers, you can do a more thorough pruning to remove selective branches all the way to the ground and prune the overall size back by about one-third.
  • Annabelle Hydrangeas (aka Smooth Hydrangeas)
  • Incrediball Hydrangea
  • Invincibelle Hydrangeas
  • Panicled Hydrangeas
  • Limelight or Little Lime Hydrangeas
  • Tardiva Hydrangeas
PANICLED HYDRANGEAS ARE NEW-GROWTH SHRUBS These varieties bloom during the current season’s growth, so pruning them back when they are dormant encourages healthy growth in the spring and abundant flowering.  Dormancy begins in late fall after all of the leaves have dropped and continues through winter and into early spring. You can cut shrubs back nearly to the ground.  If you have the Annabelle varieties, sometimes it is good to leave 18-24” of the old stems in place to help support the new growth and reduce flopping. Need Help? If you need help with your pruning, please call us at 847.866.1930. We are happy to help you! Learn more about our garden and landscape design and maintenance capabilities.