The sight of a row of scarlet runner beans in full flower is magic

“So Jack jumped up and dressed himself and went to the window. And what do you think he saw? Why, the beans his mother had thrown out of the window into the garden, had sprung up into a big beanstalk which went up and up and up till it reached the sky. . .”

– from Jack and the Beanstalk

IF ONE had to choose a plant that characterised both the magical powers of the vegetable world and the pleasures of growing your own, any one of the climbing beans would surely be high on the list Perhaps its the thrill of watching that sudden explosion of growth soon after the first small shoots appear above ground, when the stems begin their crazy scramble skywards, curling, twirling and looping themselves around anything nearby that will lend support.

There’s pleasure, also, in the sight of a row of scarlet runner beans in full flower, a tall mass of crimson-red blossoms and heart-shaped leaves. Or perhaps it’s the enjoyment to be had in picking the tender green pods in midsummer, as they dangle in heavy clusters on the plants.

In the OPW's walled Victorian kitchen garden, gardeners Meeda Downey and Brian Quinn are growing both climbing runner beans (an early variety called Red Rum) and climbing French beans (the outstandingly productive variety Cobra, which has an Award of Garden Merit from the RHS).

“For whatever reason – probably the better weather this year – the yields are way up on last summer, particularly the French beans. We’ve been harvesting both of them since mid-July, and getting a couple of bucket-loads off each of them about twice a week,” says Meeda.

“But you need to do that anyway if you want them to keep on cropping,” adds Brian. “Otherwise, if you leave even a few pods to get very large, the plant will switch from producing flowers to producing ripe seed. But by picking regularly, we expect to have beans right up until the beginning of September.” The OPW gardeners sowed the seed of both the French beans and the runner beans in the nearby heated glasshouse in late April, before planting them out (about 80 of each) in late May. “But I think well take a gamble next year and direct-sow into the ground instead, but a month later,” says Meeda. “We’re curious to see the difference.”

Both gardeners are agreed that this year’s newly-built, extra- sturdy, timber-and-wire supports (over 2m tall) have also made a big difference to the vigour and productivity of the plants. “Definitely, without a doubt,” they say in chorus.

“In previous years, if you got a sudden summer gale, it would rock the supports, damage leaves, flowers and beans and loosen the roots.

Even worse, it might rip a few plants out of the ground – and that was after anchoring the original supports (which were made from hazel rods) at ground level with extra timber pegs. So we learnt our lesson the hard way, and this year we built them extra strong and buried the legs extra deep.” grins Meeda.

The problem of inadequate support is a common one when it comes to climbing beans, as both the height and weight of a mature plant when heavily laden can take gardeners by surprise.

A 3m-long, double-row of climbing runner beans can reach a height of 2.5m-3m and produce over 27kg of beans, while the stringless, round pods of the climbing French bean Cobra (a huge cropper) can grow up to 20cm long, with each individual plant producing between 700gm and 1kg of sweet, fleshy beans.

Problem is, its only as the plants and the crop approach maturity that the importance of proper support (and a sheltered site) become obvious. But by then, it’s too late to put things to rights.

Of course, heavy crops only come after proper preparation of the soil, which is something that Brian and Meeda worked hard on getting right. The young plants went into weed-free and well-raked soil that was heavily manured last autumn and then rotovated in spring. “Climbing beans like a sunny, sheltered site and are greedy feeders so we also sprinkled the organic fertiliser OSMO around the roots at planting time,” explains Brian. “We also protected the young plants against slugs slug pellets, which are organically-approved) and made sure they were well-watered, as dry soil around the roots means a smaller crop.”

Problems with flower-setting and pollination (the first caused by sustained high night temperatures, the second by cold weather) can sometimes lead to low yields of runner beans, although not so with French beans which are self-pollinating.

While the OPW gardeners have experienced no such difficulties, other GYOers who have may be interested in a newly-introduced variety of runner bean called Moonlight.

Specifically bred to crop heavily even in poor weather or high temperatures, it’s being described as the very first self-pollinating runner bean.

Not only beautiful to look at, it’s also highly productive with giant pods. And while it does grow tall, it doesn’t reach quite the heights that Jack’s beanstalk did. So there’s no need at all to worry about angry ogres.

WHAT TO: sow, plant and do now

Sow: beetroot, broccoli raab, carrots (look out for variety Nanco, endive, kales (as CCA), kohl rabi, Florence fennel, komatsuna, land cress, lettuce, mibuna, mizuna, mustards, pak choi, spring onions, Chinese cabbage, red cabbage, radish, rocket, winter spinach, Swiss Chard, turnips, winter purslane

Plant:sprouting broccoli, chicory, French beans, Brussels sprouts, cabbages, calabrese, cauliflowers, kale, leeks, second-cropping potatoes (eg Carlingford).

Do:continue harvesting, continue sowing seed and pricking out/ thinning seedlings, weed/ hoe beds, net young brassicas, soft fruit and fruit bushes, cover carrots with Bionet, spray non-blight resistant potatoes with Dithane to protect against blight, pinch out side basal shoots and stake tomatoes, feed tomatoes, celeriac, celery, pumpkins, watch out for garden pests.

• The OPW's Victorian walled kitchen garden is in the grounds of the Phoenix Park Visitor Centre, beside the Phoenix Park Café and Ashtown Castle. The gardens are open daily from 10am to 4.00pm

• Next week Urban Farmer will write about harvesting sweetcorn

• Fionnuala Fallon is a garden designer and writer