What is the “Chelsea Chop”, and why bother?

The “Chelsea Chop” is a QUICK and EASY technique you can copy from professional nurseries to make sure you get more summer and autumn flowers in your garden over a longer period.  It is quicker and easier than “deadheading” and costs nothing but a few minutes of your time.

How does it work?

By cutting back some of your summer and autumn flowering “herbaceous perennials“ (cottage garden plants) in late spring, you can make them produce more flowers that will bloom later.

If you “chop” HALF of your flowering perennial plants and leave half alone, the flowering period could easily be doubled in length, and you will get more flowers in total.  If you only have one clump of a plant, cut down the front half, leaving the back half untouched. The back will flower first, and the front will flower a little later, and a little shorter in height. If you have several clumps you could cut down some but not others.

A variant of the method is to reduce ALL of certain types of plant in height by half or more, to make them flower more compactly. This works with the taller kinds of sedums and reduces the chance of them flopping. e.g. Sedum ‘Herbstfreude’ (‘Autumn Joy’) and Sedum telephium varieties.  It will also work on taller phloxes, heleniums etc – they’ll flower later and lower, and need less (or no) staking.

How to do ‘The Chelsea Chop’

Cut back appropriate plants by one third to one half, cutting just above a strong-looking buds (or pair of buds).  Use sharp secateurs or scissors, shears, or a sharp thumbnail if you have one!

Although not a key part of the “Chelsea Chop” process, this is also a good time to give the plants a bit of TLC if you haven’t already:

• Check for disease and damage done by slugs, snails and insects
• Scatter some slow release fertiliser and lightly hoe it in
• If the soil is dry, give it one good watering
• Cover the soil surface with composted bark or homemade compost (not peat which goes dusty, has little nutrient value and is not environmentally friendly). This will keep in moisture and improve soil.

When?

Late May, around the time of Chelsea Flower Show, hence “Chelsea Chop”. But if you’re too busy watching Chelsea on TV, a week before or after is fine too.

Later care

Do you know how much difference “deadheading” (cutting off old flowers) makes? Some plants can flower for three months instead of one, giving you three times the value!  Give it a try – take out some secateurs with your drink on a nice summer evening.  Last year my helenium sunflowers were still colourful at Christmas!

What plants respond best to the Chelsea Chop (and to deadheading)?

Summer and autumn flowering perennials like Astrantia, Campanula (Bell flower), catmint (Nepeta), Coreopsis, Day Lilies, daisy type flowers like Echinacea, Helenium, Rudbeckia and Shasta daisies, Gaillardia, Geranium, Lychnis, Monarda (bergamot), Border Phlox.

If in doubt, try it on part of a plant and see what happens!

It doesn’t work on shrubs, although some later flowering shrubs (those that flower from July onwards) can be cut back in spring and may flower later than usual as a result.