HOW TO… divide summer-flowering perennials

As they mature, clump-forming perennials make new productive growth on the outside edges of the plant, leaving the middle section to die off. Loosen the clump all the way around with a fork until it can be lifted out of the ground. Use two forks, back to back in the centre, to prise it apart into new useable sections. Use a garden knife or spade if the clump is too solid for forks to penetrate.

Lift and plant the new divisions into revitalised soil incorporated with organic matter.