When to prune your hydrangeas can be a bit of a complex topic, and because of this, it gives gardeners a bit of anxiety. Fall feels like the natural time to do pruning because so many plants benefit from being cut completely back at this time of the year.
Pruning timing all comes down to what type of hydrangea you have growing in your garden. Once you have this information, you can make an educated decision on when you should do your pruning.
The most common problem I hear is, “They just didn’t bloom this year.” There is more than one reason this can happen, but pruning at the wrong time is at the top of the list. Due to the hype of losing blooms, we have all become a bit timid about pruning. Let’s dig deeper into hydrangea pruning to understand the best timing for each species and tips to make this garden task a breeze!
The Short Answer
Hydrangeas produce flower buds in two different ways: on old wood or on new wood. Because of this, the timing of pruning can become complicated. If you know what type you are growing, you can make an educated decision. If you are still determining what you are working with, it is best not to prune in the fall. Pruning your hydrangeas at the wrong time can result in a summer without blossoms in your garden.
The Long Answer
Hydrangeas do not often require pruning, but there are times when it can be beneficial. These shrubs can become unruly and need a fresh start. Other times, pruning can help rejuvenate a plant. Let’s break down the differences and determine when to prune.
Old Wood vs. New Wood
There are many different varieties, which come from about six different species. Each species is a bit different, but the important difference to note in pruning is when each species produces its flower buds.
Determine if you have a plant that flowers on old wood or new wood.
Varieties that grow their flower buds on old wood will produce them toward the end of the summer or early fall. While old wood hydrangeas will still produce new stems and foliar growth in the spring, these new stems will not produce the cherished blossoms. Flowers will only develop on the older wood.
Pruning in late winter or early spring encourages new growth and abundant blooms in the upcoming season.
Those that grow their flower buds on new wood will not produce that new wood until spring. These hydrangeas offer more flexibility when it comes to pruning.
Hydrangea species breakdown:
|Old Wood Bloomers||New Wood Bloomers|
|Bigleaf Hydrangea (Hydrangea macrophylla)||Panicle Hydrangea (Hydrangea paniculata)|
|Oakleaf Hydrangea (Hydrangea quercifolia)||Smooth hydrangea (Hydrangea arborescens)|
|Mountain Hydrangea (Hydrangea serrata)|
|Climbing Hydrangea (Hydrangea anomala)|
When to Prune Old Wood Types
Varieties that bloom on old wood don’t require regular pruning.
Bigleaf, mountain, and climbing hydrangeas are all species that produce their flower buds on old wood or wood at least one season old. These will produce flower buds shortly after the current blooming period ends.
These species do not typically need to be pruned regularly. Reasons for pruning could be wanting to maintain a certain size or shape, removing any damaged branches, or rejuvenating an older plant.
Old wood hydrangeas should be pruned as quickly after blooming as possible. Pruning while deadheading is a great way to ensure you are not snipping off any newly produced flower buds. You do not need to prune these hydrangeas in the fall.
When to Prune New Wood Types
Varieties that bloom on new wood in spring offer flexibility in pruning.
The pruning of panicle and smooth hydrangeas can be more flexible than old wood types. These new wood bloomers will not produce their flower buds until spring. The flower buds appear on new growth from the current season.
While there are smaller, or dwarf, species of panicle and smooth hydrangeas, these shrubs will get a bit larger than the other species. Often, these hydrangeas will be pruned to about knee height or at ground level. This is not always necessary, but it is a gardener’s preference.
Pruning of new wood varieties should be done at any point after blooming, including fall. Any cutting must be done by late winter to avoid snipping off any flower buds. If your hydrangeas are large, consider leaving a few canes in place. These canes can offer support for newer branches which are producing very large blooms.
What About Reblooming Types?
Reblooming varieties like ‘Endless Summer’ are favored for their double blooms in one season.
Reblooming types, such as ‘Endless Summer’, are popular and beautiful plants. These hybridized hydrangeas bloom twice per season, while most others will only produce one set of blooms. This works because reblooming hydrangeas produce flower buds on both old and new wood.
To be safe, it is best to prune these immediately after blooming has ended, which may occur in late summer or early fall. Treat your reblooming hydrangeas like old wood hydrangeas to salvage next year’s blossoms.
Cutting canes to the ground can promote more blooms, and removing old canes promotes better health in new wood types.
Whether you decide to tackle or forego a fall prune for your hydrangeas, a few key points will help you along the way.
- Using the correct tools will make everything much easier. I like to use classic hand pruners for this job. They are small and fit easily in my hands, but they are strong enough to cut through hydrangea stems.
- Prune one cane at a time, looking back at your progress. You can always make a second cut.
- It is helpful to remove spent flowers so you get a better view of the shrub’s shape.
- If your hydrangea is a new wood bloomer, cutting the canes back to the ground can help promote a more prolific bloom.
- Remove older canes first. Removing these old canes or dead wood will help the overall health of your hydrangea. This will increase airflow within the shrub, limiting the risk of fungal diseases.
- Take a look at your hydrangea. Flower buds are easy to spot. If you see the flower buds present on the stems of your hydrangea, do not prune!
Remember that you may not need to prune at all. It is not required. Yes, there can be benefits to this gardening task, but often, hydrangeas will thrive without any pruning at all.
Ultimately, you do not need to prune hydrangeas in the fall. Do not let pruning stress you out. These plants have gained a reputation for being high maintenance, but that is untrue. If you are unsure what type of hydrangea you have, skip pruning for a season so you can do some additional research. If you are okay with missing a season of flowers because you need a rejuvenating prune, just go for it. These flowering shrubs are resilient and will survive. Happy pruning… or not!