Runner Beans
Introduction
Runner beans are one of the most beautiful sites on a vegetable garden in July and August. Climbing high up a wigwag of bean poles with beautiful red and white flowers, runner beans can look stunning. So good in fact that many people choose to grow them simply for decoration.
The hardest part of growing runner beans can be picking the pods at the right time, when young and tender as flat pods, when they can be topped, tailed, chopped into pieces, and then boiled or steamed.
Planting
- Planting depth: 5 cm
- Planting spacing: 25 cm between plants, 50 cm between rows
Harvesting
- Young pods have superior taste, older pods develop strings
- Pick and cook straight away for the best flavour, alternatively blanch and freeze
(inside)
(outside)
(fresh)
(stored)
= jar, = freeze, 
= store
Varieties
Runner beans are a popular vegetable to grow, with a choice of red or white flowered varieties that produce delicate flowers from July onwards that herald the setting of the bean pods. The beautiful flowers are a sufficient reason to grow the vegetable, providing a dramatic cascade of colour as the plants grow up wigwams or other supports, whether on an allotment or at home in a vegetable garden. There are also dwarf varieties of runner beans suitable for growing in pots on a patio.
Runner beans are typically eaten young when the bean pods are at about 25 centimetres or 8 inches in length, before the beans have started to swell inside the pods and the shell of the pods have started to yellow. The bean pods are topped and tailed, and then cut into two centimetre, or one inch slices, and added to stir fries, pasta dishes, soups, curries, and casseroles.
When eating and preparing runner beans, a common problem is the pods developing strings along the outside edges that make them less enjoyable to eat. There are runner bean varieties that are bred to avoid this problem and are referred to as ‘stringless’ varieties. Strings can also be avoided by picking the pods young. Picking young bean pods will also encourage the plants to set more beans, increasing the size of the harvest.
Runner beans are originally from South America, and are frost sensitive plants that will not survive cold nights. However, runner beans perform less well in hot dry summers, as although the plants may flower, hot nights may considerably reduce the number of flowers that set bean pods. To help overcome this problem, runner bean varieties have been developed that have been crossed with French beans (that are more reliable). Self pollinating varieties of runner beans can have higher conversion rates of flowers setting bean pods, leading to larger harvests. In dry summers, watering bean plants at night to avoid dry roots can boost harvest size.
If left on the plant, runner beans will mature inside the pods to provide seed for next year’s harvest. The beans are edible, but they must be cooked by boiling vigorously for at least 10 minutes to remove toxins that can cause food poisoning (like red kidney beans), and then simmer longer to soften. Dried beans may have more toxins than fresh beans, and will need additional soaking for 12-24 hours before cooking. Young bean pods have less toxins than mature beans, but it is always advisable to cook runner beans thoroughly (by following a recipe from a trusted source) and never eat them raw. This is an introduction to cooking runner beans, the amount of toxins will differ per variety so you may want to check this before growing (and cooking).
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Growing
Runner beans like a loose soil, as their roots dive down deeply to search for nutrients and water. They will grow best in a rich soil full of well rotted compost or manure, although in my experience they have always grown well wherever I have put them. It is recommended to prepare your runner bean bed the autumn before, digging a deep trench and mixing in rich compost.
Runner beans germinate easily and reliably. If sowing direct into the soil, plant two per bean pole and pinch out the weakest if both germinate. It is worth keeping a few pot germinated plants in reserve. Snails love runner beans, and you may find that you plant several replacements before the seedlings mature sufficiently to escape this threat.
My preferred way of growing runner beans is to create an A frame around two rows of bean poles 50 cm apart, with the poles spaced 30 cm apart. The beans may need a little encouragement to find the poles, and I loosely tie the young plants to the poles using twine. Once they have found the poles there is no stopping them.
Runner beans are a naturally vigorous plant and in hot weather they will grow quickly – provided their roots never dry out. It is best to avoid over watering when the plants are young as this may encourage them to become ‘bushy’ with too many leaves. As soon as you can see flowers, it is the ideal time to start to water regularly. Applying a thick mulch will help conserve water in the soil and suppress weeds.
When the plants have reached the top of their support, pinch out the growing tips. Left unchecked, a runner bean plant can easily grow to 2.5 metres in height, so diverting the energy into flowers and pod development will help boost the harvest.
The pods are best picked young, before they develop ‘stringiness’. The faster you cook them after picking, the more of the natural sugars you will enjoy. Otherwise these sugars will turn to starch. If you have a glut of beans, it is worth picking them young and freezing them (or giving them to appreciative friends and family) rather than letting them harden and mature on the bush.