Runner Bean

Introduction

Runner beans (Phaseolus coccineus) are a classic crop in UK gardens, prized for their long, tender pods and showy red or white flowers. Vigorous and high-yielding, they thrive in the UK climate and are ideal for vertical growing up canes, wigwams, or trellises. With proper care, they provide an abundant harvest all summer long, making them a favourite for both beginners and experienced growers.

Types and Timing

Traditional runner beans produce long green pods, but modern varieties are stringless, offering improved texture and flavour. Popular types include ‘Scarlet Emperor’, ‘Polestar’, and ‘Lady Di’. White-flowered types such as ‘White Lady’ are also available, producing slightly smoother pods.

Runner beans are frost tender and should be sown after the risk of frost has passed. Sow indoors in April-May for an early start, or direct sow outdoors from late May to July.

Site and Soil Requirements

Runner beans prefer a sunny, sheltered spot, though they will tolerate partial shade. They need deep, fertile, moisture-retentive soil. Traditionally, gardeners dig a trench in autumn, fill it with compostable materials, then cover with soil to create a rich, moist bed for planting.

They are heavy feeders, so well-rotted manure or garden compost is essential for strong growth.

Propagation & Planting

Sow seeds 5cm deep in pots or root trainers indoors, then harden off and plant out once frosts are over. If sowing outdoors, place seeds in double rows, 20-25cm apart, with 45cm between rows.

Provide strong supports before planting. The classic method is a wigwam of canes or parallel rows tied at the top to form an “A-frame.” Plants will naturally twine around supports as they grow.

Growing & Maintenance

Keep soil moist, especially during flowering and pod formation, as drought can cause flowers to drop. Water regularly at the base rather than over the foliage. Mulching helps retain soil moisture.

Feed plants with a high-potash liquid fertiliser once pods begin forming. Regular picking encourages plants to continue cropping throughout summer.

Pinch out the growing tips once plants reach the top of their supports to encourage side shoots and pod production.

Harvest and Post-Harvest

Runner beans are usually ready to harvest from July through September. Pick pods when young and tender (around 20cm long), before the beans inside swell.

Harvest regularly - every 2-3 days - to keep plants producing. Pods are best eaten fresh but can also be blanched and frozen for later use.

Troubleshooting & Pests

• Flower drop is the most common issue, often caused by dry soil or high temperatures. Keep soil moist and consider misting flowers to encourage setting.

• Slugs and snails can damage young seedlings. Protect with barriers or pellets.

• Aphids may cluster on growing tips; squash them or wash off with water.

• Poor pollination can reduce yields - planting near pollinator-friendly flowers helps.

Tips from Growers / FAQs

• Do runner beans need supports? Yes, they are climbing plants and need tall canes or netting.

• Why are my flowers dropping? Usually due to drought or heat; water consistently and mulch well.

• Can they grow in pots? Yes, but choose deep containers (at least 40cm) with canes for support.

• How long do they crop? From July until the first frosts if picked regularly.

• What’s the difference from French beans? Runner beans are more vigorous, have larger pods, and thrive in the UK’s cooler climate.

Quick Reference Table

• Sowing: April-May indoors; May-July outdoors

• Spacing: 20-25cm apart, rows 45cm apart

• Depth: 5cm

• Supports: Wigwam or A-frame of canes

• Soil: Rich, fertile, moisture-retentive

• Harvest: July-September

• Special notes: Keep well-watered to avoid flower drop

Resources & References

• RHS - Runner Beans

• Gardeners’ World - How to Grow Runner Beans