As May draws to an end it is time to carry out one of the simplest but most effective ways of keeping certain perennials in good shape and flowering for longer. It is known as the Chelsea chop and is so-called because its timing, late May, coincides with the world-famous RHS Chelsea Flower Show in London.
The aim is to delay flowering and encourageI also find it brilliant for bushy perennials such as Nepeta, which tend to flop outwards and expose their empty woody centres when stems get too long. By reining them in with a good prune in late May, you can keep them neat and encourage a second flush of flowers later in the summer. If you have several of the same type of plant dotted around the garden, try Chelsea chopping them at different times to stagger their displays.
