When to prune forsythia – it's the key to breath-taking spring displays, but only if you time it right

Known for its glorious spring flowers, forsythia is popular in gardens across the UK. But to encourage the best displays, you'll need to learn when to prune forsythia.

It's safe to say forsythia is among the brightest spring-flowering plants – it's one of the best shrubs for full sun, lapping up the sunshine and putting out vibrant blooms in return.

'Forsythia is one of the first shrubs to bloom, often flowering before its leaves emerge,' says Christopher O'Donoghue, one of the co-directors at Gardens Revived.

Sadly, forsythia isn't one of those plants you can leave to their own devices – it absolutely needs to be pruned if you don't want it to become an ungainly mess of bare roots and patchy flowers. Knowing how to prune forsythia is one thing, but timing is everything if you want to avoid spoiling next year's flowers.

Christopher O'Donoghue

A gardener with over a decade of experience under his belt, Christopher set up Gardens Revived with his brother, Andrew, in 2018 to create a thriving family business. Together, they have worked on residential gardens, listed buildings and gardens, flower shows and large estates with some exceeding 70 acres – many with historical significance.

When to prune forsythia

Forsythia produces some of the brightest springtime flowers around, but only if you learn when to prune forsythia, because timing is key.

But when is the right time? Well, it revolves around the flowering period – after flowering, to be exact.

'Forsythia flowers in spring on strong young growth, which means that the best time to carry out routine pruning is just after it has finished flowering,' explains Heather Birkett, garden and outdoors manager at the National Trust's Acorn Bank in Cumbria.

Still wondering when to prune forsythia? Flowering usually finishes around late April or early May, but you'll know it's time when the blooms fade and the plant stops producing new flowers.

Why prune as soon as flowering has finished? 'It allows the plant to create new strong growth over the summer which will flower the following spring,' explains Heather.

'You need to wait until just after the brilliant yellow blossoms have faded in early spring,' agrees Steven Bell, gardening enthusiast and the CEO of Paving Shopper.

Time it wrong, and you could be hindering the following season's blooms.

'Avoid pruning too late in the season, as it will likely remove buds for the following year,' warns Christopher.

Pruning too early can also lead to a decline in flowers, because there's a chance you'll be removing buds that are yet to bloom.

If you've neglected your forsythia and it's a little overgrown, it might need renovating – or hard pruning, as it's otherwise known. Luckily, forsythia responds well to this process – but as always, you'll need to pick the right time to do it.

When to hard prune a forsythia

Winter is the perfect time to hard prune a forysthia shrub, because that's when it's dormant.

'Forsythia is a very forgiving shrub,' says Heather. 'If it has become very overgrown, you can cut it back as hard as you like in the winter before it develops new leaves.'

There is one temporary drawback to hard pruning, though. 'The plant will not produce any flowers in the first spring after it has been hard pruned,' warns Graham Smith MCIHort, gardening expert at LBS Horticulture.

However, in the long-term, renovating a forsythia shrub will encourage even better flowering. You could even split the task over a couple of years to keep part of the plant blooming.

'The entirety of an old forsythia shrub can be pruned in a year, or you can spread the pruning over two years if you would prefer to keep some of the plant's existing structure or flowers,' Graham explains.

What you'll need

Now that you know when to prune forsythia, it's important to make sure you have the right tools for the job.

You'll want to have the following to hand:

• Secateurs like the Wolf-Garten Bypass Secateurs from Amazon
• A pruning saw like the Kimura® Samurai Pruning Saw from Amazon
• Long-reach loppers like the Kent & Stowe Telescopic Tree Lopper from The Range
• Gardening gloves like the Verve Leather Gardening Gloves from B&Q
• A trug to catch your clippings in like the Draper Garden Caddy from B&Q

FAQs

Does forsythia flower on old wood?

Yes – forsythia blooms on the previous year's growth, which is why the best time to prune forsythias is immediately after flowering. That way, the plant will have enough time to develop new growth for next year's flowers.

What is the flowering period for forsythia?

Forsythia flowers in the spring, usually from late March until April or even May.

'Providing a striking display when many other plants are still dormant, this hardy shrub adds a burst of warmth and signals the arrival of the new growing season,' says Christopher from Gardens Revived.

Now that you know when to prune forsythia, you're well on your way to making your bee garden ideas a reality – the blooms are a hit with pollinators.