Enorma is a popular variety, especially with competition growers, with straight, long pods, 30-32cm in length. Red flowers with purple seed. Good flavour.
The runner bean, commonly cultivated for its edible seeds and immature seedpods, are perennials but are often grown as annuals, especially in the temperate zone. Plants flower under long day conditions, which is ideal for temperate regions.
When grown for their edible pods, the immature pods should be harvested regularly in order to promote extra flower production and therefore higher yields. The perennial roots will survive mild winters outdoors in many parts of the country, especially if given a protective mulch in late autumn, they will then give an earlier but lighter crop the following year. They can also be dug up in late autumn and stored like dahlias in a cool but frost free place over winter and replanted in the following spring.
The plants might need some protection from slugs since these creatures adore the young shoots in the spring.
Runner beans grow well with carrots, cauliflowers, cucumbers, cabbage, leek and celeriac. They are inhibited by alliums and fennel growing nearby.
Like all members of the Leguminosae family, this species has a symbiotic relationship with certain soil bacteria which form nodules on the roots and fix atmospheric nitrogen. Some of this nitrogen is utilized by the growing plant but some can also be used by other plants growing nearby.
Pre-soak the seed for 12 hours in warm water and sow in mid spring in a greenhouse. Germination should take place within 10 days. When they are large enough to handle, prick the seedlings out into individual pots and plant them out after the last expected frosts. The seed can also be sown in situ in late spring though it may not ripen its seed in a cool summer.
Leave the pods to mature and dry thoroughly on the plant. If the weather is too damp, harvest the whole plant from the base (leave the perennial root tuber if you want an early crop the following year) and hang them upside down somewhere warm until the pods are completely dry.
Flowers – raw vegetable, salad.
Leaves – raw leaf vegetable, greens.
Root – cooked, vegetable (caution).
Seedpod – raw, cooked vegetable.
Seed – cooked bean, dried & ground as flour, protein source.
The protein-rich mature seeds can be dried and stored for future use. They need to be thoroughly cooked before being eaten in order to destroy a toxic principle. They are soaked for 12 hours prior to use and are eaten boiled or added to soups etc.
Large quantities of the raw mature seed are poisonous. The toxins play a role in protecting the plant from insect predation. There are mixed reports regarding the toxicity of the root but according to at least one source it is poisonous.