How to deadhead hydrangeas – expert advice for beautiful blooms

Hydrangeas are some of the most beautiful garden shrubs with their voluptuous blooms brightening up any garden with ease. Often, however, these blooms only last a couple of weeks before turning brown and falling away. 

Luckily, there are ways to make sure your plant continues to bloom year after year and maintain your plant's overall health. Hydrangeas are an iconic addition to any garden ideas and are one of the best flowering shrubs to inject pops of delicate pastel colors into your yard. 

'Deadheading hydrangeas can help encourage new blooms on your plant and keep the hydrangea looking fresh and beautiful,' points out Anna Eklöv, plant expert and founder of LÖV Flowers (opens in new tab).

Deadheading hydrangeas is an easy way to both strengthen them and allow them to produce more flowers in the long term so that your hard work learning when to plant hydrangeas and how to grow hydrangeas pays off.  

How to deadhead hydrangeas  

Unlike pruning hydrangeas where you remove large parts of the plant to either shape or maintain the plant's size, deadheading involves only removing the buds. When you deadhead hydrangeas, you are not harming the plant but instead removing the dying blooms to allow the plant to put its energy into root and flower development rather than producing seeds. This, in turn, allows the plant to grow stronger. 

It is important to note that hydrangeas will not rebloom in the same season after deadheading, unlike many other flowers. Whilst there are some hydrangea varieties that can rebloom, regular hydrangeas bloom only once per year - deadheading hydrangeas is more to strengthen the plant and bolster the blooms for the following year as well as prepare for winterizing hydrangeas.

In order to deadhead hydrangeas it is important to know what variety you have, explains Rachel Crow, garden editor for Homes & Gardens. ‘Bigleaf hydrangeas should be deadheaded when the first bout of flowers appear in the spring, whereas smooth hydrangeas should be deadheaded as soon as the flowers begin to fade to allow for a second, smaller bloom in the fall.’ 

The process for deadheading hydrangeas remains the same no matter the variety you have planted, however. Start with a pair of sharp pruning shears and locate a dying or dead bloom - these are distinguishable by their faded, brown color and often fragile, papery texture. 'Always use good sharp secateurs which are disinfected regularly to prevent infection entering the cut stem,' advises Angela Slater, gardening expert at Hayes Garden World (opens in new tab). 

'To deadhead hydrangeas, take each flower that’s on its way out and follow the stem down to the next set of large leaves,' explains Anna. 'You should see tiny buds in the crease between the stem and the leaf. Cut the stem about 1cm above that new bud.'

It is best practice to leave as much stem on the plant as possible, especially for big leaf varieties, so the plant can set its buds for the following year.

When to deadhead hydrangeas  

There are a few options when it comes to deadheading hydrangeas. ‘Deadheading can be done wither right after flowering, late winter at the end of the season, or early spring before the next season begins,’ suggests Rachel. It can depend on what it is you want to achieve, and how much time you want to spend deadheading your hydrangeas and your hydrangea companion plants. 

Deadheading your hydrangeas frequently throughout the growing season will keep the plant neat and preserve the plant's energy to create new blooms. 'If you can’t stand having the hydrangea looking past its best, all you need to do is cut off the spent bloom at the next pair of leaves down the stem,' says Angela. For reblooming varieties, you can deadhead the shrub again as the second set begins to fade but do not do this any later than mid-August.

'You can deadhead throughout the blooming season but stop deadheading the shrubs around mid to late autumn,' recommends Anna, 'this helps keep the buds alive that will become flowers next spring.' Removing these could be one reason why your hydrangeas might not be blooming each year.

Angela recommends that gardeners 'cut the heads off in late spring when there is less chance of a late sharp frost. If a frost is forecast when the heads have been cut off and the new shoots have appeared, just throw a sheet of horticultural fleece, old net curtain, or old sheet over the plant to prevent the buds from becoming frosted.

'Leaving the heads on the plant over winter gives the new shoots in spring some protection from a late frost.'

What happens if you don’t deadhead hydrangeas? 

If you do not deadhead your hydrangeas no harm will come to your plant. Whilst there will be no serious upfront effects, skipping the deadheading process could have detrimental effects in the following years, however, as your plant may not produce as many blooms or as big flowers. Deadheading can also help maintain the size of your hydrangea shrubs and keep your garden looking neat.