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.
Grow them too long and you may have beautiful coloured beans, but they can be tough and chewy to eat. 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.
Runner beans are a natural source of vitamins B and C. They also contain fibre and iron.
- April – June
- Planting depth: 5 cm
- Planting spacing: 25 cm between plants, 50 cm between rows
- July – October
- Eat fresh, or blanch and freeze
Runner beans originate from the mountains of Central America. They love heat and moisture, but above all else, they really loathe the cold, whether it comes from low air temperatures or from chilling winds. There is no need to take a gamble with runner beans. The best time to sow is when warm weather arrives to stay in May or June. Many a time on the allotment I have seen runner beans planted out in late April or early May, only to see one night’s low temperature kill the lot.
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 very 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 copiously.
Applying a thick mulch after watering will help conserve water in the soil and help suppress weeds. Runner beans grow in the height and heat of summer, a time of year when the keen allotmenter would prefer not to have to work too hard! Runner beans set beautiful flowers, and taking the time out to appreciate them can be a real treat.
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.
There is a wide choice of runner beans, with variations in length of pod, bean colour, and flower colour. Dwarf varieties are useful in exposed sites exposed to strong winds.
Look out for stringless varieties, and check estimated growing time to harvest.