PLANT DIVISION
Dividing perennials is the easiest way to increase your border plants – and helps rejuvenate them too
Dividing plants gives you new sections that you can replant elsewhere, creating new plants for free. It also reinvigorates plants and now is the best time to divide summer-flowering perennials, just as they start to grow again. You don’t need to do this every year – every two to three years is usually sufficient to maintain vigour. Choose a dry day when the soil is workable – it’s particularly important that clay soil has started to dry out after winter rain. Work from a board placed on the soil to spread your weight if necessary.
How to do it
Dig around the plant Use a spade and carefully lift the plant from the soil. Shake off some of the soil so the roots are visible.
Tease plants apart If they’re too tough or tangled, separate them using two garden forks placed back-to-back and used as levers to divide the clumps. Divide into sections Make sure each contains 3-5 healthy shoots. Plant as soon as possible, backfilling around the plants and firming in place. Crocosmias and dieramas (angel’s
fishing rods) produce ‘chains’ of corms rather than a mass of roots. Instead of splitting these plants, remove any wrinkled and unhealthy looking corms and replant the intact ‘chains’ at the original depth. Trim away dead leaves and water in well. Hostas can form a congested mass of fibrous roots that can be quite tricky to separate. The best way is to slice the rootball into several sections with a sharp knife or pruning saw. It looks and feels quite brutal, but be bold!