Hydrangeas are popular in the United States and several regions worldwide, mainly because of the aesthetic appeal of their flowers and how low maintenance the plants are during cultivation. Although the plants are easy to grow, you still need to cut back hydrangeas to improve their appearance and ensure healthy growth. The process of cutting back is known as pruning, a horticultural practice common in home gardening and vineyard management.
It’s too late to cut back hydrangeas when they’ve stopped flowering and formed new buds. The exact time they stop flowering depends on what hydrangea variety you have, and you must identify this before you make any pruning decisions.
I wrote this article as a guide for pruning, so it’s only right I start by telling you when not to prune. I will also provide insights into everything you need to know about cutting back hydrangeas. Keep reading to learn more.
When Is the Best Time To Cut Back Hydrangeas?
Hydrangeas are broadly classified into old wood blooming varieties, new wood blooming varieties, and reblooming varieties. Old wood blooming hydrangeas grow flowers on shoots from the previous flowering season, while new wood blooming varieties produce buds on new growth. Of course, reblooming hydrangeas flower on either old or new wood, so they’re sometimes referred to as remontant hydrangeas.
The best time to cut back old wood blooming hydrangeas is in late summer, just as temperatures cool. The best time to prune new wood blooming hydrangeas is between late winter and early spring, just as they grow fresh leaves. You don’t need to cut back reblooming hydrangea varieties.
Prune According to Your Plants’ Flowering Period
Although these three classifications work well for hydrangeas, hydrangea species flower—and subsequently need pruning—at different times. There’s a distinct relationship between when a plant flowers and the best time to prune it.
For example, while one old blooming species might form flowers in the second week of water, another might take a few more weeks to grow its first blooms. And while the periods above are the appropriate pruning times for your hydrangeas, you’ll be able to make better decisions if you know exactly when your plants flower.
Old wood blooming hydrangeas typically bloom in early summer and include species like Hydrangea macrophylla, Hydrangea quercifolia, and Hydrangea anomala.
However, new wood blooming hydrangeas include species like Hydrangea paniculata and Hydrangea arborescens, known to begin flowering from the middle of summer up until the temperatures start to fall in late summer.
Reblooming hydrangeas produce flowers all season, and some have even been reported to keep their flowers during winter. These varieties are popular among gardeners that prefer to keep their plants indoors and require almost no pruning, but they still need some care to ensure healthy growth.
The table below summarizes everything I’ve discussed:
| Hydrangea Type | Example | Common Names | Flowering Times | Best Time To Prune |
| Old wood blooming hydrangeas | Hydrangea quercifolia | Oakleaf hydrangea | Early summer | Late summer |
| New wood blooming hydrangeas | Hydrangea arborescens | Smooth hydrangea | Mid to late summer | Late winter to early spring |
| Reblooming hydrangeas | Special cultivars of Hydrangea macrophylla | Endless Summer® hydrangea | Throughout summer | No need to prune |
If you’re still having trouble identifying what kind of hydrangea you have, I recommend contacting your local florist shop or a qualified gardener.
How To Prune Hydrangeas
Hydrangeas are popular plants that belong to the genus Hydrangea, primarily grown for their bright and colorful flowers. Today, we’ve discovered dozens of Hydrangea species worldwide, and several hundred varieties are cultivated in many homes and gardens. Hydrangea plants are beautiful, easy to recognize—despite the number of species and varieties available—and even easier to grow, so it’s no wonder many gardeners like to keep the plant.
Here’s how to prune hydrangeas:
- Identify the type and species of hydrangea you have in your garden. As I mentioned before, hydrangeas fall into three categories as far as flowering and pruning are concerned. Therefore, ensure you know what type you’re working with to be sure to prune it correctly.
- Gather and clean all the tools you’ll need for pruning. You’ll need bypass pruners, lawn waste bags, pruning shears, and garden gloves.
- Take a piece of alcohol-soaked cloth and wipe the pruning shears clean. It’s necessary to clean all the pruning tools to minimize the risk of infection to the hydrangeas. Therefore, I recommend keeping the cloth close to you throughout the pruning process.
- Deadhead the hydrangeas. Cut below the brown blooms and above the healthy foliage to deadhead. This step is crucial to the overall pruning process, and you should cut the flowers one by one.
- Cut back dead, weak, and injured stems. Start with dead branches, then remove weak and injured stems. Ensure you don’t prune too far down so that there’s some shoot for the plant to grow back from during the blooming season.
- Prune the plant to the desired shape. You can skip this step if you’re doing some “hard pruning,” although I recommend doing it if this is your first time pruning. You need to cut off a few of your Hydrangea’s highest-growing branches.
- Reduce the size of the plant. Some hydrangeas can overgrow their original space, and you may need to remove branches to the main stem altogether to maintain it. However, take care not to remove all the healthy branches, so the plant can quickly grow back later.
These steps will work for all hydrangeas, but you might need to make a few adjustments depending on the hydrangea species you’re pruning. For example, climbing hydrangeas only need light pruning, and you can stop once you get to the fifth step.
Similarly, some hydrangea plants only need to be deadheaded, as they don’t grow wild enough to require pruning. Of course, your pruning is only as beneficial as when and how well you do it, so ensure you prune at appropriate times. You can check the table above if you’re unsure of the best time to cut back your hydrangeas.
Should You Cut Back Hydrangeas for Winter?
Like many other flowering plants, you need to cut back your hydrangeas for aesthetic reasons and thin out the shoot to improve plant growth. However, pruning also benefits many plants by preparing them for the harsh winter and ensuring bigger blooms during the flowering season. Therefore, it’s typical to wonder if these benefits can be harnessed when pruning hydrangeas.
You should cut back hydrangeas for winter if they’re new wood blooming varieties. You can prune old wood blooming hydrangea varieties for winter, but there’s a chance you can damage the new buds and prevent the plant from blooming in the summer.
You can prepare the plants for winter by following the pruning process above, but be careful that you’re working with new wood blooming hydrangeas.
If you have to prune old wood blooming hydrangeas, I recommend deadheading the hydrangeas instead. Deadheading will protect the plants, prevent overcrowding and ensure you don’t damage the new buds. I previously wrote an article about deadheading hydrangeas, and you can read more about it here.
Instead of pruning them, you can also deadhead reblooming and new wood blooming hydrangeas in preparation for winter. However, it’s necessary to note that while deadheading has its benefits, your plant may specifically need pruning to survive the winter and flourish next blooming season.
The best time to cut back new wood blooming hydrangeas for winter is in late winter. Meanwhile, you should prune and deadhead old wood blooming varieties after their last flowers have bloomed in late winter.
What Happens if You Don’t Cut Back Hydrangeas?
Pruning affects blooming, flower head size, and even overall plant growth. You can adjust the pruning intensity based on how you’d like your hydrangeas to turn out. “Hard trimming” typically results in larger plants and larger blooms, while “soft trimming” results in relatively smaller but more blooms.
If you don’t cut back your hydrangeas, they won’t grow properly or bloom quite as much. They may grow wild, develop thorny stems, and have scattered and unattractive flowers if you don’t cut them back. Pruning is immensely beneficial to your hydrangea plants, and you shouldn’t take it lightly.
Before pruning, ensure you take note of the initial size of the hydrangeas and make replanting and overall pruning decisions based on this fact. If the hydrangeas were thick and big before pruning, they’ll usually be at least that size when it grows back.
Also, hydrangeas don’t need to be pruned as much as other plants, and I recommend deadheading if you’re not preparing for winter.
Key Takeaways
Hydrangeas are pretty popular, and it’s usually too late to prune them if they’ve formed new buds.
You need to determine what kind of hydrangea you’re working with and make an efficient pruning decision. Old wood blooming hydrangeas are typically best pruned in late summer, and you’re better off pruning new wood blooming hydrangeas between late winter and early spring.
You can find out what type of hydrangea you have based on when it flowers. Follow the guide in this article to prune them correctly. Don’t forget to be careful when pruning.
