What Is the Chelsea Chop and Should You Try It on Your Plants?

Additional reporting by Emily Hannemann

If your late-summer perennials flop into your path, the increasingly popular Chelsea chop may help. This pruning trend has recently gained notoriety on social media in the United States, but the catchy name originated across the pond to create fuller, bushier plants with more numerous—if smaller—blooms. Named for its timing during England’s Chelsea Flower Show in late May, it delays flowering and reduces the need for staking.

What Is the Chelsea Chop?

The technique is simple. Using shears or hand pruners, cut back growth to one-third or one-half the size, cutting to just above a leaf or leaf bud. If the plant is tall enough to still have strong leafy growth after you cut it back, it’s ready.

When to Chop

English gardeners chop in May, but timing depends on the growing season of your region. Geoffrey Johnson, founder of Depend on Planet Earth and a community garden educator in Savannah, Georgia, says he chops in mid-February to keep pace with growth in Savannah’s warmer climate, but northern gardeners might need to prune later. The Royal Horticultural Society (RHS) says the closer to flowering you prune, the later flowers will bloom.

Why the Chelsea Chop Works

By cutting back young stems, the Chelsea chop encourages the growth of side shoots, creating stronger stems. Geoffrey says, “Perennials such as echinacea, black-eyed Susans and Shasta daisies benefit from it greatly. It’s very helpful for tall plants or if you have high winds.” In addition to the neater habit, he says, “I just love seeing flowers, period. And of course, for bees, butterflies and other pollinators out there, the more flowers, the better.”

Best Plants to Chop

You can use the Chelsea chop on many tall, late-summer perennials that are prone to flopping, such as asters, tall sedums, catmint and tall phlox. Hardy geraniums and heleniums also respond well. According to the RHS, most vigorous late bloomers tolerate the technique.

If you grow any of the following in your garden, it can work for you:

• Joe Pye weed
• Coneflower
• Hyssop
• Penstemon
• Goldenrod
• Obedient plant
• Black-eyed Susan
• Bee balm
• Coreopsis (Tickseed)

When Chopping Might Not Be the Right Choice

• This method isn’t for pruning spring-blooming flowers because you may lose the bloom altogether.
• The Chelsea chop will likely delay flowering and reduce the size of your flowers. If you like big blooms, sit this trend out.
• If you have a short growing season, the plant may not have time to bloom.
• If you’d rather not cut back all the blooms—for example, if you’re concerned about the availability of blooms for pollinators—you can always half-Chelsea chop and leave the rest of your plants alone.

Pro Tips for a Better Chop

• After chopping, water well and top-dress the plants with compost to help them rebound.
• To extend your bloom season, try this version: In a large plant, cut back only the front half of the plant, allowing the back to grow tall and bloom early. In a drift of plants, experiment with leaving some intact for a longer bloom. This approach gives one plant two bloom windows!

Sources

• Royal Horticultural Society, “Chelsea chop“
• Wild Ones, “The Chelsea Chop“
• Longfield Gardens, “The Chelsea Chop: How and Why to Prune Perennials“