Summer bedding plants will continue to flower into autumn if you carry out this crucial task in August – don't miss out on a second flush of blooms

The hot weather has made gardening a challenge this year, with many of us struggling to keep plants looked after and watered in the heat. But if your garden has lost its glow and the flowering plants are looking a little jaded, all is not lost.

Deadheading is one of the easiest, but most important August gardening jobs you can be doing right now. Focus on deadheading your summer bedding plants now and you’ll encourage a fresh flush of flowering that will see your garden right through to autumn.

‘To keep summer bedding plants blooming throughout autumn, it’s important to deadhead regularly,’ says Chris Bonnett, plant expert and founder of online garden centre Gardening Express. ‘Deadheading redirects plant energy into fresh blooms rather than the dead flowers. And there are certain bedding plants it’s worth keeping a close eye on during August.’

Read on to see which plants you should focus on and how to deadhead bedding plants most efficiently for a second flush of flowers.

Why deadheading bedding plants is a must

‘August is the prime time for deadheading your plants to keep them healthy as fall approaches,’ says Hanfei Niu at NiuPlants at Palmstreet app. ‘Once a flower wilts, a plant focuses on seed production instead of blooming and making new flowers. By removing old blooms before they set seed, it encourages the plant to produce more flowers instead, in another attempt to reproduce.’

‘August is also ideal for deadheading because plants are still growing but daylight is starting to shorten, so this keeps them blooming for the autumn rather than letting them go to seed. Regular deadheading keeps your plants looking beautiful, fresh and healthy all season long and keeps their energy and roots stronger as autumn approaches,’ adds Hanfei.

How often should you deadhead?

‘It really depends on the plant as to how often you’ll need to deadhead throughout August,’ advises Craig Wilson, co-founder and gardening expert at Gardeners Dream. ‘But usually around once a week is a good starting point to ensure you’re checking regularly for any new dying flowers that can be removed.’

‘Deadheading a little from time to time and often is best,’ advises Hanfei. ‘Check every few days, rather than waiting for all your plants to look tired and doing everything all at once.'

Which bedding plants benefit most from deadheading?

‘Focus on repeat-flowering favourites such as geraniums, petunias, marigolds, cosmos, dahlias and sweet peas,’ advises Mark Hewett Divisional Sales Manager for Garden Tools & Accessories at Wilkinson Sword. ‘By removing spent blooms before they have a chance to set seed, plants redirect their energy into producing fresh flowers rather than seeds, extending the display for several more weeks.’

‘Pinching out sweet peas is always a top priority,’ advises Hanfei. ‘If they set seed pods, they'll stop flowering almost entirely.’

How to deadhead effectively

‘Pinching the stem between your thumb and finger to snap off the stem is an easy way to deadhead,’ says Chris. ‘For more woody stems, snip with secateurs. And if you’re deadheading masses of small flowers, try using shears for speed.’

‘It’s worth keeping a close eye on certain bedding plants during August,’ advises Chris. ‘When deadheading marigolds, the spent flower heads can simply be pinched off and they’ll continue blooming during autumn. For deadheading petunias, pinch out faded, withered blooms along with their tiny stalks to prevent rotting. This will also stop the plants from looking untidy throughout late summer.’

‘When it comes to geraniums, simply snap off flower stalks from the main stem for fresh buds and to tidy the plant. And for deadheading cosmos, use snips to take off the old heads which will stop seed pods from forming and to encourage new growth.’

‘Dahlias will need secateurs for deadheating,’ adds Chris. ‘Cut old flower stems back to the closest leaf node or down to the main stem.’

5. Get your technique right

‘Don't make the deadheading mistake of simply pulling off faded petals. Instead, remove the entire flower stem back to the next healthy leaf or developing bud which will encourage stronger regrowth and a tidier plant,’ advises Mark. ‘It is essential that you make clean cuts without damaging healthy growth, so using snips or secateurs is always best when deadheading blooms on thicker stems.'

‘Use a sharp, precise tool to help prevent unnecessary damage to surrounding stems and foliage. Long-nosed pruning snips are ideal for the job, like these Straight Pruning Snips, £14.99 from Wilkinson Sword, with steel blades that deliver lasting sharpness and clean, accurate cuts, which makes it easer to work in tighter spaces between plants,’ adds Mark.

‘When deadheading, I’d always advise cutting back a certain amount but not too much and not just the flower,’ says Hanfei. ‘Follow the stem down to just above the first set of healthy leaves and snip off just the petals leaves to prevent an ugly stub that can rot.’

‘Use clean, sharp tools, like snips or pruning scissors. And ensure that they have clean blades to reduce the risk of spreading disease between plants,’ adds Hanfei.

Deadheading essentials

Don't stop at deadheading

‘Don't stop at deadheading,’ adds Hanfei. ‘Make sure to pull off any yellowing or brown leaves at the same time as you deadhead to keep plants looking neat and reduce disease risk.’

‘And keep watering bedding plants consistently, especially those in containers and hanging baskets, which dry out fast in August. Stressed, dry plants stop flowering regardless of deadheading,’ Hanfei adds.

‘Give long-leafed plants a trim too. For annuals like petunias that have gotten overgrown, a harder trim (cutting back by a third) alongside deadheading often triggers a fresh flush of compact growth,’ advises Hanfei. ‘And remember to separate deadheading from pruning. Shrubby plants (like lavender) are better lightly trimmed after flowering rather than deadheaded bloom-by-bloom.’

Give your bedding plants some care now, and they should continue to provide you with colour into the early autumn months.