Why Climbing Beans Earn Their Space

If you have only a few square metres to spare, climbing beans are one of the best bargains in the kitchen garden. A single wigwam of six or eight plants can crop for ten weeks or more, producing far more pods than the same ground given to a dwarf variety. They grow upwards rather than outwards, so they slot neatly beside a shed, along a fence, or at the back of a bed where they will not shade your lettuces.

The catch, of course, is the weather. British summers are generous with light but stingy with heat, and a wet July can leave French beans sulking and runner beans dropping their flowers before a single pod sets. Choosing the right varieties — and giving them a little shelter and warmth — makes the difference between a glut and a disappointment.

Runner Beans: The Traditional Choice, With Caveats

Runner beans are the classic British climber, and rightly so. They are vigorous, hardy once established, and they crop over a long season. The old-fashioned varieties such as 'Scarlet Emperor' and 'Painted Lady' are still worth growing, partly for the flowers, which are a magnet for bees.

Their weakness is heat and drought. When temperatures climb above about 25°C, runner beans struggle to set pods, and flowers drop. In a cool, damp year they are in their element. Two things help enormously:

• Choose self-fertile or "stringless" types bred for reliability, such as 'Moonlight', which sets well even in poorer summers.
• Keep the roots consistently moist. A thick mulch of grass cuttings or compost after planting makes an enormous difference.

If you have struggled with runners before, don't give up — but do plant a backup row of French beans.

Climbing French Beans: The Reliable Workhorse

For sheer dependability in a British summer, climbing French beans are hard to beat. They are less fussy about temperature, cope better with a cold snap, and many varieties will keep producing until the first frost if you pick them regularly.

'Cobra' is a superb starting point: heavy-cropping, stringless, and tolerant of cooler spells, with distinctive violet flowers. 'Blue Lake' is another old favourite, with round pods that freeze beautifully. If you fancy something different, 'Blauhilde' produces long purple pods that turn green on cooking, and 'Goldfield' gives you tender yellow wax beans on a climbing frame.

The key with French beans is not to sow too early. Cold, wet soil is the enemy — seeds rot before they sprout. Wait until the soil has warmed properly, usually from mid-May in the south and early June further north.

Giving Beans a Head Start

In most of the UK, direct sowing is a gamble. Raising plants under cover and planting them out once the soil is warm gives you a two- to three-week advantage and much more even germination.

• Sow in deep pots or root trainers from late April, one seed per module, about 5cm deep.
• Keep them at around 15–18°C — a cool windowsill or unheated greenhouse is ideal once they are up.
• Harden them off gradually over a week before planting out, ideally in early June.
• Water the planting hole before you set the plant, then firm gently and water again.

If you do direct sow, do it in a warm, sheltered spot and cover the row with fleece or a cloche until the seedlings are through.

Support, Shelter and Site

Climbing beans need something to climb, and they need it in place before planting. A wigwam of eight canes, tied at the top, is the simplest structure; a horizontal row of canes leaning against a frame suits a long bed better. Whatever you use, make it sturdy — a wigwam of heavily cropping beans in a gusty August wind carries a surprising amount of sail.

Site matters as much as support. These are tender plants that hate cold wind almost as much as cold soil. A south- or west-facing wall, a sheltered corner by a hedge, or the lee side of a shed gives them a warmer microclimate and noticeably earlier cropping. If your plot is exposed, run a length of windbreak netting along the prevailing wind side.

Rotate your beans each year. Growing them in the same spot season after season encourages soil-borne problems and exhausts the ground, even though beans fix their own nitrogen.

Watering, Feeding and Picking

Once flowering begins, beans become thirsty. Water deeply twice a week in dry spells rather than little and often, and aim the water at the roots rather than the foliage, which helps to limit mildew. A mulch in late June will keep moisture in and suppress weeds.

There is some debate about feeding, but a light liquid feed high in potash once pods start to form supports a longer cropping window. Avoid anything too rich in nitrogen, which encourages leafy growth at the expense of pods. As the plants start to fade, a foliar feed can help keep them going into September.

Above all, pick often. Beans left to swell on the plant signal that the job is done, and cropping tails off quickly. Go round every two or three days, taking pods while they are young and snapping cleanly. Surplus pods freeze well — blanch for two minutes, cool, and bag them — so nothing goes to waste.

Making Your Choice

For a dependable British harvest, plant a maincrop of climbing French beans such as 'Cobra' or 'Blue Lake', and add a wigwam of runner beans for the flavour and the flowers. Choose self-fertile runner varieties if your summers are cool, sow under cover, plant out into warm soil, and keep the water and the picking going. Do that, and a modest corner of the plot will keep you in beans from July right through to the first frost.