Should you Prune Hydrangeas in the Fall?

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 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. 

Old 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.

New Wood 

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.

When to Prune Old Wood Types

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

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 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. 

Pruning Tips

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.