Lasting Landscapes by Carol

The Chelsea Chop

It’s time for the Chelsea chop! What is that you ask? The Chelsea chop is a pruning technique that keeps rangy perennials neater as the season advances. When done right, Chelsea chopping helps to extend bloom time and produce more flowers. The name Chelsea chop refers to the Chelsea Flower Show held in London each year. Those living in England start chopping in late May when the show is held. For those of us who live in North America, chopping should be done between late May and late June.

Not every perennial responds well to a hard pruning in early summer, but there are a number of plants I regularly cut back including asters, mums and tall perennials that tend to fall over when they start to bloom. I’m not a fan of staking, so I prefer the Chelsea chop method for maintaining a nice form. For Asters like ‘Lady in Black’ and ‘October Skies’ I chop the plants in half. This delays the bloom a bit, but most importantly improves the plants stature so it looks tidier when it flowers. I use the same technique for my Chrysanthemum Sheffield Pink and Coreopsis tripteris.

Lasting Landscapes by Carol
A half-chopped Chrysanthemum shows how the technique works.
Lasting Landscapes by Carol
Cutting back perennials like this Aster ‘Lady in Black’ can be stressful, but plants respond quickly by sending out new growth. This additional branching often results in more flowers.
Lasting Landscapes by Carol
If I didn’t but back this Coreopsis tripteris, it would flop onto the driveway. Instead, I chop it and it stays upright when in flower.

For plants like Phlox paniculata, experts recommend either cutting back the entire plant or staggering pruning, only cutting every other stem or so. This helps to prolong bloom time, since some of the stems will bloom first and others later. I’m told there are a number of perennials that benefit from the Chelsea chop like Solidago. I’ve never tried chopping my Solidaga caesia or even my Aster divaricatus, but this year might be the time for me to try the technique on them so I can see the results for myself.

Lasting Landscapes by Carol
I cut alternate stems on this Phlox paniculata to prolong the bloom time.

I encourage you to chop away before the end of the month. You’ll be rewarded with neat and tidy plants, lots of flowers and extended bloom times. My guess is you’ll love the technique so much you’ll want to set a recurring reminder each year for this important garden activity.