We’ve received a lot of questions about hydrangeas. Namely, our clients and subscribers want to know when to prune them. Should you prune them in early spring when they’re just coming in? Or should you wait until early winter?
In short, our answer is…it depends. There are a number of considerations when deciding when to prune hydrangeas. Continue reading below to find out when you can safely prune these lovely flowers.
Typing your hydrangeas
Hydrangeas, while beautiful, are a complex shrub. There are several different species with different traits and behaviors that will affect how and when you prune them. For our purposes, you’ll need to be aware of three different categories of hydrangeas: old wood, new wood, and reblooming hydrangeas.
OLD WOOD HYDRANGEAS
Old wood hydrangeas are those flowers that set their buds on old wood. In other words, they form their flower buds on old branches in the fall for the next season. For this reason, you shouldn’t prune these shrubs.
For those that simply must prune old wood hydrangeas, pruning in spring and limiting your cutting to only the dead branches is essential to avoid killing off that year’s new buds.
It’s important to plan for these types of hydrangeas in your landscaping. They should be planted in a location that will allow them to grow without annual pruning.
Oakleaf, big leaf, and mountain hydrangeas are great examples of old wood flowers (when they’re not rebloomers, that is, and we’ll discuss that in a following section).
NEW WOOD HYDRANGEAS
New wood hydrangeas are those flowers that set their buds on new wood. That is, they form their flower buds on new branches in the spring when they’re ready to bloom. This means you can prune them in late fall or early spring and still expect the plant to form new buds and bloom later that year. If you prefer, you can also prune them in the fall, depending on the type of look you enjoy. Smooth and panicle hydrangeas are examples of new wood flowers.
NEW AND OLD WOOD HYDRANGEAS/REBLOOMERS
Reblooming hydrangeas bud once on old wood and again on new wood during the season. This means we recommend that you treat them like you would an old wood hydrangea. Prune them in early spring for dead branches. And if you must prune these types of hydrangeas, be aware that you are removing some of the blooms and will set the blooming cycle back but not all your blooms will be gone (that’s a benefit to these reblooming types)!
Final Thoughts
If you’ve been wondering why your hydrangeas aren’t blooming, and your practices don’t align with what we’ve written above, you may be starting to realize why. Pruning the wrong hydrangea at the wrong time can prevent blooming for an entire season or more.
So be careful to properly identify the type of hydrangea you’re dealing with and, especially with old wood species, be careful to only prune them at the correct times. You should see next season’s flowers come in big and bright if you follow our directions and take good care of your plants. Until next time!
