How to grow runner beans

We’ve been growing runner beans in British gardens since Tudor times, but then they were considered an ornamental plant rather than a vegetable. Their bright-red flowers began to appear once cooler nights arrived, because this high-altitude plant is equatorial and it thrives on shorter days that aren’t too hot. Eventually gardeners must have realised that the pods were edible.

Runner beans have become one of the most useful vegetables and they crop from late-July until the autumn, roughly 12 weeks after being sown or planted. There are two main problems however - they’re susceptible to frost and summer gales, so it's important to plant them in sheltered positions after all risk of frost has passed.

Choosing your runner bean varieties

Plant breeders have been selecting earlier flowering varieties with long fleshy pods for centuries and there are heritage white-flowered and red-flowered varieties. They vary in their needs.

Traditional red-flowered runner beans

Traditional red-flowered varieties can suffer in hot weather, due to heat, and they have a tendency to drop their flowers if night time temperatures exceed 16C. Red flowers are also more likely to be pecked by birds. They prefer cooler, rainy summers and we’re tending to have hotter, drier conditions.

‘Polestar’
A superb stringless variety with smoother-skinned, bright-green fleshy pods and a great traditional flavour. Early and prolific, a heavy August cropper producing a long succession of thick fleshy pods until late.

‘Enorma’ AGM
Commercially grown because it crops so heavily, with long slender pods. The flavour’s superb and it’s often grown for the show bench as well.

‘Scarlet Emperor’
A favourite exhibition runner bean variety with long straight pods, but it’s heavy cropping and tasty too. Harvest from August to September.

‘Prizewinner’
Foot-long straight beans, which are succulent and flavoursome.

'Streamline'
A long variety of runner bean that can be left on the plant longer than some other varieties.

‘Red Rum’ AGM
The first red-flowered runner bean to crop, producing stringless medium-length pods. Often over by August, so do grow a late variety too.

White-flowered runner beans

Generally white-flowered runner bean varieties tolerate more heat, so do better in warmer summers, but conversely they tend to do badly in cooler, wetter summers. Many think white-flowered varieties have more flavor, however.

‘White Lady’ AGM
A runner bean that sets well, fairly high yielding. Fleshy, smooth and stringless pods. An excellent variety of runner bean with a strong flavour. Tends to be late.

‘White Apollo’
Long, straight, smooth, stringless pods with an excellent flavour. Produces prolific crops over a long period for continuous yields throughout summer.

‘White Emergo’
Long, smooth pods with a superb flavour, but best picked when still young and tender.

Hybrid runner beans

The British seed company, Tozer Seeds, set about hybridizing the best runner bean varieties with heat-tolerant, self-fertile climbing French beans in order to produce runner beans that crop whatever the weather. These recent hybrids produce plumper slightly shorter pods with a good flavour. They don’t need a pollinator either, so they will crop come rain or shine.

‘Moonlight’ AGM
White-flowered, high yielding hybrid that’s easy to pick, with smooth, fleshy pods, of good length. ‘Moonlight’ produces pods that resemble the runner bean in shape, but when snapped the pods have the plumper profile of a French bean. Self-setting, vigorous and long-cropping,

‘Snowstorm’ AGM
White-flowered hybrid with long, straight, smooth-skinned fleshy pods. High yielding and good for the show-bench.

‘Stardust’ AGM
Vigorous white-flowered hybrid with smooth, fairly fleshy High yield straight pods that are rougher in texture.

‘Firestorm’ AGM
Popular red-flowered, self-setting hybrid with slender smooth-skinned, slender fleshy pods. Excellent yield – it crops heavily and produces 9" long beans with a plump profile. Plant 'Firestorm' with 'Moonlight' for a good crop, whatever the weather.

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Top Tip

Many gardeners hedge their bets and grow some red and some white-flowered varieties and then they get a crop whatever the weather.

How to plant runner beans

There are three different ways to plant and grow runner beans.

Planting ready-grown runner bean plants

You can buy ready grown plants in late Spring. However these should NOT be planted outside until the first week of June. Keep them in a frost-free place until then and try to plant them into damp soil.

Planting runner beans under glass

You can raise your own plants using small 9cm pots.

Place one or two seeds into seed-sowing compost in late April or early May. Sow plenty so that you can gap up. Grow on under cool glass, but fleece your young plants on cold spring nights. Harden them off in May, by placing them outside during the day but DON’T put them outside until the first week of June.

Sow straight into the ground in mid-May

Timing is critical when sowing frost-tender beans into the ground, because you want them to appear above ground until the first week of June. If they come up too early they may get frosted. Mid-May is perfect.

Use 8 ft high sturdy canes or hazel rods. Build an A-frame for rows, and then strengthen it with horizontal canes that sit above the meeting points. You can also make an X shape and tie the canes halfway up and some gardeners think this improves the yield.

Use 8 canes for a tripod and tie them at the top using jute string.

Once the structure is in position, sow three seeds round each cane plus a few spares, either in the middle of the tripod, or at both ends of the row.

Protecting runner beans from frost

These climbers, originally from mountainous areas of Central South America, are very frost tender and slightest frost will kill them. Cold May nights will also check their growth and blacken the foliage, so it’s important to bide your time and wait until the first week of June before planting them outside. This is the biggest mistake gardeners make - so be patient!

Protecting runner beans from wind

A leafy row of runner beans can be ruined by strong summer gales, which we are getting more of due to recent climate change. Always try to find a sheltered position, away from prevailing winds. Tripods are far more wind resistant than rows, because the wind can go round them more easily. They slot into smaller gardens easily and one or two tripods will supply enough beans for a small household. Eight tall canes are arranged around a circle and tied at the top, for each tripod.

Making a runner bean tripod

• Place a dustbin lid on the ground
• Use eight tall canes and place the first four opposite each other (as though they were the four main compass points) roughly 12 inches away from outer rim of the lid so that you’re creating a larger circle.
• Slant them into the ground so that they make a tepee shape.
• Remove the dustbin lid and place that last four midway between the compass points and tie securely at the top.
• Place 3 beans round each cane and plant a handful of beans inside the centre of the tripod as spares for gapping up. Water seeds well in dry weather until they germinate.

Where to plant runner beans

Always choose a sheltered warm position with good light for runner bean plants, as they can suffer in windy positions.

When to plant runner beans

Runner bean plants, whether grown at home or bought, will need to be hardened off and not planted out until the first week of June.

How long do runner beans take to germinate?

Runner bean seeds will take between 17 - 21 days to come through, on average.

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Slugs and runner beans

Slugs can be a problem for young runner bean plants, so frisk them at dusk in the early stages.

Watering runner bean plants

Water well in dry weather, especially in early summer.

Blackfly on runner beans

Red-flowered beans sometimes get blackfly. Pinch out any affected tips and destroy. Don’t spray - it’s a food crop.

When to harvest runner beans

Begin harvesting the early pods when they get to 6 - 8 inches, to encourage more. You should get 8 weeks of picking on average.

Growing a second batch

If it’s a hot summer, you can sow another lot of seeds in July, for a later crop.

Why aren’t my runner beans cropping?

Runner beans failing to crop are probably due to the weather. Warmer summers and hotter nights. Unfortunately if the night-time temperature consistently exceeds 16C (62F) runner bean flowers often fail to set - however much you water the plants or spray the flowers. This is particularly true with red-flowered varieties grown from dark, mottled seeds, however varieties do differ.

Pale-seeded, white-flowered runner beans show much more tolerance to warmer nights. They crop more heavily in warmer summers. However if we get a cool summer, red-flowered runner beans perform better than white-flowered ones. So it's a good idea to sow both.

The most heat tolerant beans of all are French beans.

Visit our fruit and vegetable section for more growing guides, including how to grow broad beans and how to grow peas.

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