When and how to prune Annabelle hydrangeas – expert tips for a bumper display of beautiful blooms

Discover the ideal time to cut back these popular hydrangeas - and some expert do’s and don’ts for pruning them

White flower head of an Annabelle hydrangea
(Image credit: Getty Images/John Caley)

Annabelle hydrangeas are adored for their large blooms and it's possible to get lots of these stunning flowers by pruning the shrub each year. Not only will trimming help give you a good display, but your hydrangea will look neat and stay in top health.

When it comes to hydrangea pruning, it is important to understand the variety you are cutting. Annabelle hydrangeas are simple to prune as they produce their flowers on new wood each year.

They do not require lots of tricky pruning and the shrubs will continue to bloom every year even without any trimming. Whether you want to keep the hydrangea tidy, or prune harder to retain a more compact shape, there are a few simple steps to follow when it comes to when and how to prune Annabelle hydrangeas.

Annabelle hydrangea shrub with white flowers

Annabelle hydrangeas like to grow in full sun

(Image credit: Getty Images/skymoon13)

What are Annabelle hydrangeas?

Annabelle hydrangeas (Hydrangea arborescens 'Annabelle')  are a hugely popular hydrangea variety that are native to the US and also known by names including smooth hydrangeas or wild hydrangeas. 

The deciduous shrub produces large and round white flower heads in summer. When you plant an Annabelle hydrangea they can grow to over six feet in height and width, but can be kept more compact through pruning.

White flower head of an Annabelle hydrangea

Annabelle hydrangeas produce large and showy flower heads

(Image credit: Getty Images/John Caley)

When to prune Annabelle hydrangeas

Not all hydrangeas are pruned at the same time. The best timing depends on the variety - treating all hydrangeas the same would be a hydrangea pruning mistake that could rob you of a year’s worth of flowers. 

Annabelle hydrangeas produce blooms on new growth, which means you can keep the shrub compact and encourage new flowering stems through annual pruning. It is the same with other popular panicle hydrangea types, such as when pruning limelight hydrangeas

Wait until the hydrangea is dormant before doing any pruning, as cutting when the shrub is still actively growing will stimulate it to put on new growth that will be damaged by the cold winter weather. 

Lorraine Ballato, author of Success with Hydrangeas, warns that pruning before dormancy will ‘distract the plant’ from going fully dormant. While you can trim the plant at any time from late fall onwards once dormancy has started, she advises waiting until late winter or very early spring to prune.

‘Watch the plant and as soon as you see the buds starting to swell in advance of leafing out, get those pruners going,’ says Lorraine.

A dormant hydrangea will have dropped all its foliage, making it easier to prune as you can clearly see the shape and structure of the shrub. Hydrangeas left unpruned offer aesthetic benefits in a winter garden, which can also be a reason to hold off pruning until just before the new growth starts. 

The old flower heads protect the new developing buds from frosts in late winter - this can be beneficial for anyone with Annabelle hydrangeas in colder climates.

Lorraine Ballato
Lorraine Ballato

Lorraine Ballato is a hydrangea expert and the the author of the international best selling book 'Success with Hydrangeas', available at Amazon. She is also an in-demand speaker throughout the US and the resident hydrangea expert at the New York Botanical Garden. 

Annabelle hydrangea in winter

Annabelle hydrangea flower heads look good left in place for winter

(Image credit: Alamy/Freeman Keats)

How to prune Annabelle hydrangeas

Always use clean and sharp garden tools to trim hydrangeas, it will help make clean cuts and prevent disease. Using dirty or blunt pruning shears or loppers is a pruning mistake that can harm the health of your hydrangea. It is also recommended to disinfect tools prior to pruning. 

Annabelle hydrangeas are simple to prune. Always start by removing dead, diseased, and damaged wood. Then the shrubs can be trimmed into shape by thinning out overcrowded old and tall stems and removing weak growth.

Lorraine Ballato warns of cutting Annabelle hydrangeas all the way to ground level to hard prune the shrub. She claims this is a common misconception told to gardeners and it can cause issues when the shrub regrows, so she recommends an alternative solution if you want to cut stems back harder.

‘The reason is that the plant will not be able to grow stems strong enough to hold up the flowers and they will flop as soon as the first raindrop hits them,’ says Lorraine. ‘Cutting the old stems down to about 2-3 feet will leave a nice framework to support those new stems and flowers.

‘You could make the job easy by just using a hedge trimmer at a 2-3 foot height and then removing every third stem at ground level.’

When pruning hydrangeas you must take care not to damage any developing buds in the plant’s crown that will carry the new flowering growth for the year.


Can you prune Annabelle hydrangeas in the spring?

The early spring is an ideal time to prune Annabelle hydrangeas, just before new growth begins. As the plant will be devoid of leaves due to dormancy, it provides a great chance to see the structure, make unobstructed cuts, and encourage a flush of new wood to carry the year’s flowers. 

Do not prune too early in the spring, especially in colder climates or US hardiness zones, as it could leave the hydrangea susceptible to frosts that can get into pruning cuts.

Can you prune Annabelle hydrangeas in the fall?

Annabelle hydrangeas can be pruned from late fall onwards, once they enter their dormant period. Pruning them earlier in fall, when they are actively growing, will stimulate a new flush of growth that will not be hardy enough to survive the cold of winter. 

The hydrangea has a natural cycle and pruning too soon in fall could distract it from going dormant at the right time. Pruning in late fall may be seen as beneficial if you want to tidy the yard as part of your fall gardening checklist, but if you have colder winters then it is advisable to hold off trimming until late winter or early spring.

Can you prune Annabelle hydrangeas in summer?

The shrubs should not be pruned during the summer months, bar a spot of deadheading. Trimming back hydrangeas in summer will encourage the growth of new wood, which will not bloom that summer and any buds that develop are likely killed by the winter frosts. 

Just like cutting back hydrangeas in the fall, growth that occurs after late summer pruning will be damaged by the cold weather in winter.

Should I deadhead Annabelle hydrangeas?

It is not absolutely necessary to deadhead Annabelle hydrangeas. As the plant produces flowers on new wood, the act of deadheading will not encourage more flowers that season. 

However, there can be merits to deadheading and it may depend on your garden style or preferences. As David Cohen, from flower wholesaler Badais International, says: ‘Deadheading can improve the plant's appearance and prevent it from diverting energy to seed production.’

You may actually want to snip the blooms of Annabelle hydrangeas before they fade, as they can be used as cut flowers for arrangements. 

The blooms of Annabelle hydrangeas are suitable for drying to use in bouquets, or as decorations. Drying hydrangeas can be a simple technique to preserve the blooms for many years.

Drew Swainston
Content Editor

Drew’s passion for gardening started with growing vegetables and salad in raised beds in a small urban terrace garden. He has gone on to work as a professional gardener in historic gardens across the UK and also specialise as a kitchen gardener growing vegetables, fruit, herbs, and cut flowers. That passion for growing extends to being an allotmenteer, garden blogger, and producing how-to gardening guides for websites. Drew was shortlisted in the New Talent of the Year award at the 2023 Garden Media Guild Awards.