Climbing beans are tall, viny plants that grow upwards off the ground by twisting round any support that the vines can find. Prized for their tender, fleshy pods, the two most popular types are runner beans (the first choice among British gardeners) and French beans (which are not French at all).
Both types originated in the New World and found their way to Europe after Columbus’ voyages of exploration. The plants are frost sensitive and heat loving, and despite their immigrant status, they are well-adapted to growing outdoors during the British summer.
Both French beans and runner beans are also available as dwarf versions. There are many varieties of dwarf French beans in the catalogues; dwarf runner beans generally are not so common. Though dwarf varieties are popular, there are many reasons why the climbing ones make a better choice for home gardeners. Not only do they have a longer harvest period, but they can produce higher yields from the same number of plants. They are also easier to pick – the pods are more visible, and harvesting can be done standing up. The only disadvantage is the need to erect some sort of structure to support the plants, but this is not a particularly difficult or expensive job.
Growing the beans
Because they are tall growing, climbing beans should be sited in a sheltered spot protected from the wind – otherwise, they can be blown over. The soil should be well-drained, well-fertilized and worked to a good tilth, allowing the plants to thrive rather than just survive.
After the soil is prepared, it’s time to erect a structure that will support the vines. A number of support systems have been devised, though probably the quickest and cheapest one to construct is a wigwam made from bamboo canes 1.8 or 2.4 meters long. Stick 8 canes into the ground equidistant in a circle 1.2 to 1.5 meters in diameter, then tie them together at the top with strong twine. If growing more that one wigwam, leave about a meter spacing between the edges of each – this will give enough room to harvest.
Once the wigwam has been erected, start the crop by sowing three seeds 4 to 5cm deep at the base of each cane. If the soil is too cold, the seeds will rot rather than germinate, so sowing should be delayed until the temperature warms up. In South England, this will normally be sometime from mid to late May, though it could be later in chilly springs. When germination is complete, thin the seedlings down to leave the two strongest at each post.
An earlier crop is possible by first producing transplants in a greenhouse, conservatory or south facing window. Sow 3 seeds in a module tray or small pots, and thin down to the two strongest seedlings after emergence. Sowing can commence as early as the middle of April, and the young plants will be ready to go outside about four to six weeks later. At this point, transplant two plants next to each cane, watering the soil to settle them around the roots.
As the plants start to grow, twist the vines around the canes to train them upwards. After this initial bit of help, they will begin to climb on their own.
Under no circumstances should the soil be allowed to dry out. Pay particular attention during dry spells, being sure to water regularly once flowering begins. Spraying runner bean flowers with water on hot, dry days is often recommended to help pod set, but this is a gardening myth that has no obvious benefits.
Picking the bean pod
There is a tendency to pick the pods when they are old and too tough to be thoroughly enjoyed. When this happens, the walls get stringy, particularly with runner beans, and the seeds inside start to swell up with starch. It is better to pick the pods when they are young – not only are they sweet and tender, but the plants will produce bigger yields.
Pest and diseases
Both French and runner beans are free of most bothersome diseases, which makes control measures such as spraying unnecessary. Runner beans can get black fly (aphids), but generally infestations do not spread and eventually get controlled by natural predators. Unfortunately, slugs and snails will devour young plants, but nightly collection trips to the garden will put a stop to that. To prevent problems from developing, rotate your beans by growing them only one year in four in the same part of the garden.
Runner beans can have red or white flowers, or a combination of both colours, and a few varieties are now available that have salmon pink flowers. The pods, however, are always flat and green. There is an extensive choice of varieties, including old favourites and several new varieties. Some new varieties have had a few genes of French beans bred into them to make the pods smoother skinned and less stringy. Two new varieties worth trying are Firestorm (red flowered) and Snow Storm (white flowered).
The pods of climbing French beans are more variable in shape and colour. They can be green, yellow, purple or speckled; and are round or flat and short or long. Three high yielding varieties are Cobra (round podded and green) and Hunter (flat, wide and long and green podded), and Cosse Violette (flat and purple podded).
To conclude on beans
Climbing beans require little effort to produce good yields of pods. Pests and diseases are seldom problematic, and there is a good selection of varieties to suit most tastes. This is an easy-to-grow vegetable that is tops for convenience and dependability – what more can a vegetable give?
© Michael Michaud