Runner Beans

Runner beans (Phaseolus coccineus) are frost-tender, vigorous legumes grown for abundant long green pods. Most cultivars are twining climbers that use vertical space efficiently and flower in red, pink, white, salmon or bicolours before setting clusters of beans. Dwarf cultivars grow only about 45cm tall, crop more quickly and suit containers or exposed gardens, although they yield less and for a shorter period.

Climbers need a sunny sheltered site, rich moisture-retentive soil, sturdy 2.5m supports and frequent watering. They thrive in cool, wet summers and may struggle to set pods during hot dry weather. When plants begin cropping in midsummer, pick young pods every two or three days. Regular harvest prevents beans maturing on the vine, which would suppress further flowers.

Runner bean pods and seeds must be cooked before eating because raw pods and beans are harmful. Harvest at about 20–25cm while pods snap cleanly, remain stringless and contain small pale seeds.

Choose climbers for the heaviest, longest crop and dwarf cultivars for small containers or windy sites. Consider pod length, thickness, stringlessness, flavour, flower colour and performance in hot weather. Hybrids with French bean parentage tend to set pods more reliably in difficult warm conditions. AGM cultivars have performed well in RHS trials.

Recommended varieties

Runner bean ‘White Lady’ AGM

Attractive white flowers develop into heavy crops of thick, tasty and stringless green pods.

Cultivar sourceAllotment Pro variety guide

Runner bean ‘Stardust’ AGM

A British-bred, self-fertile runner/French bean hybrid with white flowers and a heavy crop in varied weather.

Cultivar sourceAllotment Pro variety guide

Runner bean ‘Liberty’ AGM

A red-flowered climber producing large crops of long, well-flavoured pods.

Cultivar sourceAllotment Pro variety guide

Runner bean ‘Enorma’ Elite AGM

A popular heavy-cropping variety with notably slender green pods that may reach 50cm long.

Cultivar sourceAllotment Pro variety guide

Runner bean ‘Firelight’

A British-bred, virtually self-fertile cultivar with scarlet flowers and improved pod set during hot, dry summers.

Cultivar sourceAllotment Pro variety guide

Runner bean ‘Moonlight’ AGM

A runner/French bean cross with white flowers and stringless smooth pods, reliable even in less favourable conditions.

Cultivar sourceAllotment Pro variety guide

Choose a sunny, sheltered position. Weed thoroughly, then fork in at least two bucketfuls of homemade compost or well-rotted manure per square metre several weeks before planting, allowing the soil to settle. In a no-dig bed, apply organic matter as a surface mulch ahead of sowing or planting.

Install supports before plants go into the ground. For a traditional A-frame, set two rows of 2.5m bamboo canes or hazel poles 45–60cm apart. Space canes 15–30cm within each row, slope paired canes inward and tie them near the top to a horizontal pole. Leave at least 1.5m between multiple double rows.

An X-frame crosses poles lower down, placing pods within easier reach and often improving cropping, though it is less stable. A wigwam uses at least five 2.5m canes spaced 15–30cm around the base and tied at the top. Arches, netting and trellis are alternatives. Give dwarf plants short twiggy supports so pods stay off the soil.

For an early reliable crop, sow indoors from mid-April through May. Fill small pots or deep modules with moist peat-free multipurpose compost, sow one bean 5cm deep in each, water and keep above 12°C in a warm bright place. Seedlings grow quickly and need regular watering. Harden them off and plant after the final frost, usually late May or early June.

Outdoors, wait until frost risk has passed and soil reaches 12°C—typically mid-May in the south and early June in the north. Sow two seeds 5cm deep at each cane, then retain the stronger seedling. For dwarf cultivars, leave 30cm between plants and 50cm between rows.

Small potted seedlings can move to final positions once about 8cm tall in June or July. Set one climbing plant at each cane, water well and loosely tie its stem to start it twining. Dwarf plants remain 30cm apart.

For dwarf beans, use containers 30–45cm wide. Climbing beans need a stable heavy pot at least 75cm wide and 45cm deep, fitted with a 2.5m wigwam. Sow 5cm deep and 15cm apart, with two seeds per cane followed by thinning.

Runner beans are thirsty, especially once flowering and pod formation begin. Water regularly and generously in dry weather; containers need particularly frequent checks. Mulch with compost or well-rotted manure after planting to conserve moisture and suppress weeds.

Ground-grown beans in enriched soil usually need no additional feed. Feed container plants every fortnight from the first flowers with a high-potassium organic liquid fertiliser. Avoid excess nitrogen, which can favour leaves over pods.

Protect young plants from slugs and snails and monitor soft shoot tips for black bean aphid. Flowers depend on pollinators, so avoid treatments that harm bees. A sheltered, consistently moist position supports successful pod set.

Guide young stems around their canes and loosely tie any growth that comes free. Runner beans naturally twine upward, so little intervention is required after they engage with the support.

When climbing stems reach the top of a 2.5m structure, cut off further extension growth. This keeps plants within reach, reduces top-heaviness and encourages productive side-shoots lower down. Support dwarf plants with twiggy sticks rather than pruning them heavily.

At the end of harvest, cut stems at soil level and compost the top growth. Leave roots in the ground to decay because their nodules contain nitrogen fixed from the air.

Cropping usually begins in midsummer and can continue for eight weeks or more. Pick pods at about 20–25cm, while young, tender, stringless and easy to snap. Seeds inside should still be small and pale. Some exhibition-length cultivars can grow longer, but ordinary eating quality is best before pods toughen.

Harvest every two to three days, taking all ready pods. If beans mature, the plant reduces flowering and pod production. Handle vines gently and use two hands if necessary to avoid breaking flowering stems.

Cook pods thoroughly before eating. Do not sample runner beans raw. Remove remaining mature pods at season’s end unless intentionally saving seed from a suitable non-hybrid cultivar.

Frost kills young plants, so keep seedlings protected until the last frost. Poor pod set can follow dry roots, acid or infertile soil, cold wet pollination weather, excessive heat, bird or insect damage, and infrequent harvest. Enrich soil, mulch, water consistently, shelter flowers and encourage pollinators.

Blackfly forms dense colonies on tips and leaves. Glasshouse red spider mites cause pale mottling in hot dry conditions. Shieldbugs may feed on pods. Rust produces orange-brown pustules and reduces vigour. Slugs and snails attack seedlings. Rotate beans and inspect crops regularly.

Common problems