All set for the Chelsea chop?

Plantsman John Hoyland explains why you might want to take the secateurs to give your late-flowering herbaceous perennials a prune this month

- John Hoyland

HERBACEOUS perennials are now bolting out of the ground, looking vigorous and healthy. It is precisely at this moment that some gardeners, to the bewilderment of many people, will ruthlessly cut their plants back. Applied at about the same time as the flower show, the Chelsea chop, as it is known, is simply a method of pruning some perennial plants so that they produce more blooms later in the season and generally look neater.

Pruning is a job usually confined to trees and shrubs, but there are ways in which perennials can be pruned and this, the Chelsea chop, is the most popular. The Royal Horticultural Society Dictionary of Gardening explains succinctly that pruning is a mechanism for keeping plants neat and tidy, to bring them to the desired shape and to 'induce the plants to produce to the maximum those qualities for which they are grown'. This is exactly what the Chelsea chop does.

Two decades ago, American author Tracy DiSabato-Aust dedicated a large part of her book The Well-Tended Perennial Garden to the pruning of herbaceous perennials and did much to popularise the 'chop', as it is referred to by its champions. However, although the technique appears to be the ideal way to achieve tidy, floriferous plants, it cannot always be used. Perennials that are pruned in this way will never reach their true stature and their flowers are often smaller than if the plant had been left alone.