Pruning Your Hydrangeas
If you have always been confused about when and how to prune your hydrangeas, here are some tips for you.
Plants should be mulched heavily to reliably produce flowers the following year. One of the most commonly asked questions at garden centers worldwide is...
How do I prune my hydrangeas? It’s easy, really!
First, some definitions: There are three ways in which hydrangeas flower– those that flower on new wood, those that flower on old wood, and now there are some newer selections that flower on new and old wood and therefore they require little or no pruning each year.
Old Wood means branches that have been on the hydrangea since the summer before the current season.
New wood means branches that will develop on the plant during the current growing season.
When blooms appear on last year's branches (old wood):
Prune these hydrangeas only in the summer before August, before they set their bloom buds for the next year. This group of hydrangeas produces flower buds on hydrangea stems around August, September, or October for the following summer’s blooms. If those stems are removed (pruned) in the fall, winter, or spring, the bloom buds will be removed, and there may be little or no bloom the following summer (usually June/July for the northern hemisphere).
Example of a Plants Nouveau hydrangea that blooms on old wood:
Hydrangea Magical® Everlasting Amethyst
When blooms appear on this year's branches (new wood).
This type of hydrangea is determined to flower every single year, no matter how they are treated. Prune these plants in the late summer after they have bloomed. They cannot be pruned up to the point in the spring and early summer when the plants start to really grow, so don't prune much after they start to leaf out. This is also a good time to cut back any dead stems that were killed by winter.
Example of a Plants Nouveau hydrangea that blooms on new wood:
Hydrangea arborescens 'Hass' Halo
When blooms appear on both this year's and last year's branches (old and new wood).
Prune these hydrangeas only if they are getting too large for space or if you want to remove old flowers. The best time to prune them is after they flower in the late summer. If you prune them much beyond late summer, you will risk removing the flower buds that are developing on the current branches. If you live in a colder climate and do have stems die back to the ground, cut back to where you see leaves sprouting once they begin to leaf out in late spring.
Example of a Plants Nouveau hydrangea that blooms on both old and new wood:
Hydrangea Magical® Everlasting Green Cloud