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Runner beans

Marathon crops of runner beans

Runner bean
Runner bean Moonlight in July

Runner beans are the quintessential summer crop, reminiscent of cottage gardens and better times.

However, the reality is often a glut (and your family gets sick of them) or no pods at all, due to inclement weather or pests.

The aim is to strike a happy medium and enjoy this prettiest of crops.

If you garden in the north or have heavy clay soils which take a long time to warm up, sow under cover indoors in April and early May.

Fill deep pots (15cm/6in) with multipurpose compost and water well (I’ve used family yoghurt pots with success too, but you may have to pot them on).

Runner bean Moonlight
Runner bean Moonlight makes an appearance in late April

Sow two seeds per pot, 5cm (2in) deep, thinning to the strongest one after germination.

Grow on in temperatures over 12°C (54°F) in a greenhouse or sunny windowsill.

Plant out after frosts

Harden off the young plants gradually and plant out when the risk of frost has passed in June.

When the soil has reached 12°C (54°F), seeds can be station sown in their permanent positions every two weeks until the end of July.

Plant two beans at every point, then thin to the strongest. If your soil is heavy, pre-warm it by covering it with cloches for a month before sowing.

Runner bean Moonlight ready to be hardened off
Runner bean Moonlight ready to be hardened off

Runner beans thrive in a rich deep, fertile soil in full sun. A bean trench is a traditional way of preparing the soil and can be done well in advance.

Dig out a trench approx 90cm (3ft) wide and 60cm (2ft) deep. Scatter well-rotted manure, home-made compost, or even old newspapers/cardboard/kitchen peelings (not cooked) in the bottom.

Add pelleted poultry manure or similar at the recommended rate. Leave soil to settle for two weeks before planting.

When shoots have reached the top of their supports, pinch them out. Runner beans need lots of water – 5-9 litres per sqm (1-2 gallons per sq yd) every three to four days.

Beans are ready when the pods are about 15-20cm (6-8in) long, snap easily and the seeds are small and pale in colour.

Pick regularly to encourage further pod production; every two or three days.

potted-guide-logoPotted guide: runner beans

  •  SOWING TIME: April-May indoors; May-July outdoors.
  •  HARVESTING TIME: July-first frosts.
  •  PLANTING DISTANCE: Climbers – 6″ (15cm), one per cane; bush types 1ft (30cm).
  •  ASPECT AND SOIL: Full sun, rich, lots of organic matter – feed and water well.
  • HARDINESS: Frost-tender.
  • DIFFICULTY: Moderately easy, but need care – and can fall victim to pests and diseases.
  • RECOMMENDED VARIETIES: All climbers unless otherwise stated. Bi-colour: St George, Hestia (dwarf), Painted Lady, Tenderstar. White: Moonlight, White Apollo, White Lady, Snowstorm, White Emergo, Desiree. Red: Scarlet Emperor, Benchmaster, Polestar, Firestorm, Enorma, Goliath, Wisley Magic, Scarlet Empire, Red Rum.

Vital supporting role for beans

Phormium flower stems
Me and my runner bean poles, made from Phormium flower stems

The traditional way is to use a double row of inwardly sloping 2.4m (8ft) tall bamboo canes or hazel poles tied near the top to form an A-frame. These are secured to a horizontal cane across the top.

Using 10cm (4in) pea/bean netting secured to a wall makes a good alternative.

Wigwams of three or more canes make good use of space in small gardens.

My more unorthodox supports are old flower stalks of Phormium, which are light, strong and approx 8ft tall – and free.

Problems and cures

Runner bean
White-flowered varieties set better in poor weather

FLOWERS NOT SETTING: Ensure soil is constantly moist and doesn’t dry out; mulch in June. Mist the foliage and flowers, especially during hot, dry weather.

Pinch out the growing tips when plants are 15cm (6in) high. The flowers formed on side shoots usually set better.

Try pink or white-flowered cultivars, which usually set pods more easily.

APHIDS: Their honeydew often attracts black sooty moulds to grow. In most cases, the damage can be tolerated – squash colonies between thumb and forefinger – see more here.

SLUGS/SNAILS: They feed on the young seedlings. Many ways to control slugs and snails – see my in-depth page – follow the link.

NO/VERY FEW PODS: Usually caused by lack of moisture and/or poor pollination by insects/ cool weather conditions. Plant into soil with plenty of organic matter, in a sheltered site. White-flowered varieties cope with dull/cool summers better.