If you want an early crop of beans, sow the seed outdoors the previous autumn, provided the soil is still warm. Choose a hardy variety. Alternatively, sow seed outside from early spring on, depending on the weather. If the soil temperature is low, warm it by covering with polythene to aid germination. You could also sow the seed under cover, one per root trainer or small pot, taking care to acclimatize the seedlings to life outside before planting them out.
Broad beans are prolific croppers once they get going, so aim for a series of small successional sowings of 8-12 seeds, with a few substitutes in case of failures. Using a trowel or dibber, sow seeds individually at a depth of 5cm (2in). Seeds should be 23cm (9in) apart, either in double rows or in small blocks, but in either case make sure that the rows are staggered to maximise the spaces between.
Broad beans take about nine to ten weeks to mature, which means that between early and late spring you should be able to manage another one or two sowings to ensure a more prolonged, even harvest. There is no set time for a second or third sowing; just wait until the previous one has reached a height of about 15-20cm (6-8in) before sowing the next crop. Do not be tempted to sow more plants before this, however, or the second sowing will probably catch up with the first.
If you have autumn-sown beans, delay your first spring sowing until the weather is warm enough for the autumn beans to have put on some strong new growth.
Supporting the plants
Plants in exposed sites will fall over in the wind or lose stems under the weight of the swelling pods unless they are staked. Old, long, strong and twiggy prunings can be used to create an unobtrusive network of support; put these in place once the seedlings have emerged. Alternatively, plants can be tied to structures made from string roped around a series of stakes or strong bamboo canes.
Cultivating the crop
When the young beans begin to appear at the base of the plant, it is time to ‘pinch out’ the growing tips in order to concentrate the beans’ energy on pod formation. Nip off the top of the stem with two pairs of leaves attached; these can be eaten.
At harvest time
Harvest beans when they are small, before the flesh becomes starchy and the skin bitter. Take pods from the base of the plant-end work up. Because it can be easy to damage plants while picking pods, it is best to use scissors or secateurs to snip them off.
Storing and cooking tips
Broad beans freeze well, but need to be blanched first. Don’t dispose of the thinning tips; they are delicious to eat wilted in pasta or risotto dishes.
Pests and diseases
Black bean aphids can be quite a pest. They often colonize the young shoots first, where they find it easy to suck the sap. Insecticides with a physical means of action should be used only if infestations are severe, and they do minimal harm to helpful insects. If you do see aphids, immediately pinch out the tips with finger and thumb. Planting herbs to repel or distract aphids is more wishful thinking than anything else.
In early spring, pea and bean weevils are active, eating semi-circular notches into leaf edges. Plants are unlikely to be seriously damaged by this, except in very poor weather when new leaf growth is slow. Covering with fleece is the best remedy.
Two common fungal diseases are chocolate spot and rust, visible as brown or orange spots on the leaves. Chocolate spot tends to occur in damp, humid weather early in the season, and rust during dry spells later on. Neither is usually severe so they are not worth treating.