Although many gardeners have given up growing peas because they feel they take up too much space, very few seem to have given up runner beans for the same reason. Possibly it is because they are seen as better value for money and space because they continue to crop over a long period and it is possible to freeze any excess for later use. As with peas, fresh runner beans are far better than those you buy in the shops, so the effort is certainly worthwhile.
Runner beans originated in Mexico, where they have been grown for more than 2,000 years, long before the Spanish conquistadors arrived, they were introduced to Europe in the 16th century but were at first grown more for their decorative qualities than for their culinary ones. Even today their presence in a kitchen garden is notably ornamental, although the beans are usually eaten as well as admired.
Runner beans usually grow up to about 1,8m/6ft, although in good soil they will grow to 2.4m/8ft or more. There is, however, little to be gained from growing them so tall because it is difficult to harvest the topmost beans. Dwarf varieties are available for those who want them, but they have never become very popular, partly because yields are lower and partly because all the beans tend to mature at the same time. The pods are long and rather coarse in texture, much coarser than the equivalent French (green) beans. This coarseness also applies to the texture, and it is important to pick the pods young – once they age they become very stringy. Some varieties are less strings than others.
The pods are usually eaten along with the young beans, but they can be allowed to mature and the fully grown beans dried and eaten later in the year.
The general colour of the flowers is red. Hence the old name of scarlet runner beans, but there are now other colours, including white and mauve. These are very useful in decorative schemes, and they still produce a good crop of beans.
Cultivation
Beans do best in an open, sunny position; in more exposed areas they should be protected from winds, partly to prevent them from blowing over and partly because pollination is more difficult in such conditions. They will grow in quite poor soil but do best in a soil that has been well manured during the previous autumn. The traditional method is to dig a deep trench and bury plenty of compost and manure, even old newspaper. The idea is not so much to provide nutrients, although this is obviously important, but to create an area around the roots that retains plenty of moisture.
Beans must not appear above ground before the last frost has passed, so early summer is usually the earliest one can begin planting. To get them oil to a good start, sow beans individual in pots or modules and plant out when the weather is right. Alternatively, sow directly into the soil. If you are able to make an early start, it is often a good idea to sow again some three weeks later so that there is a continuous crop until the first hosts of w inter.
Before sowing or planting you will need to construct some form of support up which the beans will climb. This can be in the form of a single or double row (double is usually preferable) of poles, canes or strings for them to climb up, or it can be a wigwam or tepee – that is, a circle of poles or canes, pulled together at the top with string to form a cone. The distance between the poles or strings should be about 25cm for although they will grow closer together, it is easier to pick the beans if the plants are not too close.
Plant or sow one bean at each pole. Many gardeners sow two or three beans at each position – “one for the crow, one for the slug and one for the kitchen and remove the weaker seedlings, leaving just one. The beans are sell-clinging but may need help to go up the right pole or string, as they often seem to prefer their neighbour’s. Make sure that the soil is always moist, especially in dry periods.
Sow or plant dwarf varieties at 15 cm intervals in a single row with 45cm between rows. Pinch out any long shoots that develop. After harvesting, cut down the beans hut leave the roots to rot in the ground; they contain stores of valuable nitrogen.
Harvesting
Pick the pods as soon as the beans begin to swell, which is usually when the beans are about 15cm long. Some varieties, especially those developed for exhibition, can inconsiderable longer than this. A larger crop can be encouraged by picking regularly, putting any excess in the freezer. It is also important to pick regularly because old beans become stringy and inedible.
Storage
Beans do not keep well and should be eaten as they are harvested. The only storage method used today is freezing, although in the past they were often preserved in salt.
Pests and diseases
Slugs and snails are always a problem when the plants first emerge, and they can easily kill the entire planting. Runner beans are otherwise generally problem free, apart from possible attacks of blackfly. Powdery mildew and chocolate spot may also occur.
