Divide & CONQUER

Spring is the ideal time to divide certain herbaceous perennials to keep them healthy and vigorous and to increase your stocks of plants

Most plants that flower in summer can be lifted and divided either in spring or in autumn, as long as the soil is dry and workable. If it’s a wet and soggy autumn or you have heavy clay soil, it’s preferable to wait until spring. Spring is also the better time to divide those plants that are a little tender.

When working in borders, try not to trample the soil: use wooden planks to spread your weight and avoid compaction. First, cut down and remove any top growth. Next, work a fork all the way round the group, loosening the soil and teasing the roots away. When all the roots are free it should be possible to lift out the plant. Occasionally you will have to use a spade to slice congested plants into bite-sized clumps to get them out of the ground.

Once you have lifted the whole group, you can begin splitting. Sometimes it is possible to tear the clumps apart, but more often you will need to use two forks placed back-to-back to tease roots apart. With most perennials you want palm-sized pieces to put back. Leaving the delicate roots exposed can stress the plant, so get them planted back in the soil without delay, adding compost and fertiliser as needed.