If you want to do it now, lift the whole clump and split off the most vigorous pieces of growth - usually those round the edges. Replant the best bits in soil that has been refreshed with compost, bonemeal or a sprinkling of seaweed fertiliser.
While spring bulbs are stars of the garden, summer-flowering bulbs are starting to appear in garden centres. Look out for Galtonia candicans, a stiff-stemmed plant with flowers like an enormous white hyacinth. It grows to 4ft high. Bulbs should be planted at least 6in deep and 6in apart. They are excellent among herbaceous perennials, and flower July to September.
Sow a row of peas, and remind yourself what a proper pea tastes like. I have sown the early variety `Douce Provence' (Marshalls, pounds 1.64 for a large packet), which is sweeter than the standard early variety `Feltham First.' I've also put in a row of broad beans `Green Windsor' (Johnsons, pounds 1.45), which have short, broad pods, and beans of an excellent flavour. But you need to pick broad beans young, before the coat round the bean has turned to leather. If you grow your own, you can pick the pods at the right time. Commercial growers gain from the extra weight of more mature pods.
Heathers can be trimmed over now to remove old flower growths. Take care not to cut back into old wood. Layering is a painless way to propagate heathers. Scoop out a series of shallow bowls in the earth around the plant and fill them with sandy compost. Peg the branches down in this mixture, using bent wire or stones.