May is all about strategic tidying in the garden, from pruning spring-flowering shrubs to deadheading certain spring bulbs, and cutting back tender perennials to keep borders looking fresh.
May is also the perfect time to try the ‘Chelsea Chop’ – a simple pruning technique timed to broadly coincide with the RHS Chelsea Flower Show, which runs from 19–23 May 2026. In late spring, trim early flowering perennials by a third to a half. It might feel drastic, but it helps create sturdier, bushier plants, reduces the need for staking, and can delay flowering so you can enjoy blooms for longer.
One important thing to note: May falls within peak bird nesting season, so before pruning shrubs, dense hedging or trees, always check carefully for nests and hold off if you spot any.
‘May pruning should be light touch only,’ points out Tim Clapp, qualified botanist an head of range for Verve – B&Q’s own exclusive gardening brand. These are the plants Tim recommends pruning in May.
- Roses
- Forsythia
- Ribes
- Philadelphus
- Evergreen hedges
- Phlox
- Sedums
- Nepeta (cat mint)
- Tulips
Roses
By May, most rose varieties are either flowering or about to. A stretch of warm sunny weather will trigger strong growth and abundant buds and many roses will be at their best right now.
‘Remove spent flowers to encourage more new flowers to grow and flourish,’ says Tim. ‘Roses lie dormant for a good few months, so before the new rose comes through, deadhead your buds.’
Spring-flowering shrubs
The important thing with these is to get the timing right – and the secret is to wait until the shrubs have finished flowering. As Tim explains: ‘Spring flowering shrubs, such as forsythia, ribes and philadelphus, flower on old wood, so this is a good time to prune. Cut back stems that have flowered by one third and remove about 50 per cent of the oldest stems and wood from the base of the plant. This will keep the plant tidy and compact, ready for next year’s display.’
Evergreen hedges
Pruning evergreen hedges is mostly about keeping them in good shape so they stay dense and manageable.
‘A light trim will keep them tidy and help them from going out of control,’ says Tim. ‘Always taper the hedge so it’s widest at the base, narrowing in towards the top. This allows light to reach the base of the hedge, keeping it lush and full.’
Early-flowering perennials
May is the best time to treat early bloomers such as phlox, sedums, and nepeta to the Chelsea Chop, confirms Tim: ‘Give the plants a hard prune, removing up to half the foliage and stems. This helps to delay flowering and create an overall sturdier plant, preventing them from becoming too floppy and leggy.’
Tulips
Most tulips will be coming to the end of their show this month and will be starting to drop their petals. What you do now will affect how well they perform next year.
‘Deadheading your tulips in May needs to be a top priority,’ urges Tim. ‘After their spring flowering, pruning the dead flower heads off tulips directs the energy into forming the bulb rather than developing seeds.’
Tip: Always ensure your pruning tools are clean and sharp to avoid damaging your plants or spreading disease.
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