Diarmuid Gavin’s guide to giving your plants the Chelsea chop

Cutting your perennials back now will make them more compact and help them to produce more flowers

Later-flowering perennials such as sedum can benefit from the Chelsea chop — © Getty Images

Diarmuid Gavin

Next week sees the opening of the Chelsea Flower Show in London, an annual celebration of all things floral and horticultural. We’ll be bombarded with images of perfect gardens and perfect flowers — fantasy productions that can inspire and entertain. It’s also a handy reminder for a gardening technique known as the Chelsea chop, a method of chopping back perennials to manipulate flowering times, and is so-called because the end of May, or Chelsea Flower Show week, is when you can start to do this.

So why do we do this and what exactly does it entail? The purpose is to make the plant more compact and produce more flowers. By cutting it back now, you encourage lots of side shoots, which makes the plant bushier and produces more flower buds, though somewhat smaller flowers. It’s similar to pinching out seedlings. A big advantage is that the plants are sturdier and shorter so will not require staking. This is particularly handy for front-of-border plants so they do not flop over onto the pathway or lawn.