The Chelsea chop is a useful technique that helps control the size, shape and flowering time of certain summer-flowering plants – and late-May (around the time of the RHS Chelsea Flower Show) is the perfect time to do it.


By carrying out the Chelsea chop on your plants, you'll also encourage the production of more flowers. After you've cut back your plants, make sure you give them a thorough watering and some feed.

Discover 11 plants to Chelsea chop, below.


Cut back phlox to encourage greater production of the richly scented blooms.

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Achillea is very attractive to pollinators, especially hoverflies. There are many beautiful cultivars to grow, including 'Fanal', 'Moonshine' and 'Summer Berries'.


Campanulas are known for their lovely bell-shaped flowers, in vivid shades of blue and purple. Cut them back to encourage more of the beautiful blooms.


Asters form a rich nectar source for flying insects, and respond well to the Chelsea chop. Asters you could cut back include Aster macrophyllus and Symphyotrichum laeve (formerly Aster laevis).


Another hugely wildlife-friendly plant, you'll be encouraging plenty more blooms to grow by cutting echinaceas back. Keep an eye out for slugs and snails on young plants.


Many rudbeckias can grow so tall that they risk flopping over in windy weather. Chelsea chopping them will help to restrict their height.


Sedums are prone to becoming leggy and looking untidy. Give them the Chelsea chop to encourage a neater, more compact shape, with more flowers.


With their large, tubular flowers, it goes without saying that penstemons are a hit with bumblebees. Just some of the many stunning cultivars to grow include 'Sour Grapes' and 'Bredon'.


In the right spot, heleniums will rapidly grow skyward and often require staking. Cut them back to control their flowering height. Here's how to plant heleniums in August.


By cutting back nepeta, or catmint, you'll encourage a profusion of blooms to be produced later on, providing a later source of nectar and pollen for bees.



Not all sunflowers need cutting back. Don't cut back large, annual Helianthus, but instead go for perennial sunflowers, such as vibrant cultivars like 'Lemon Queen'.