The scarlet runner plant makes for a beautiful display with its lush green leaves with bright red flowers. The beans that grow in the scarlet runner can be cooked and eaten, and they provide fiber, protein, and potassium.
I. Appearance and Characteristics
Phaseolus coccineus, known as runner bean, scarlet runner bean, or multiflora bean, is a plant in the legume family, Fabaceae. Another common name is butter bean, which, however, can also refer to the lima bean, a different species.
This species originated in the mountains of Central America. It was most likely cultivated in the highlands of Mexico and Guatemala around 2000 BC. Most varieties have red flowers and multicolored seeds (though some have white flowers and white seeds) and are often grown as ornamental plants. The vine can grow to 3 metres (9.8 ft) or more in length, its pods can get to 25 centimetres (9.8 in), and its beans can be up to 2.5 centimetres (0.98 in) or more.
It differs from the common bean (P. vulgaris) in several respects: the cotyledons stay in the ground during germination, and the plant is a perennial vine with tuberous roots (though it is frequently treated as an annual in colder climates).
The knife-shaped pods are normally green; however, there are rare varieties bred by amateurs that have purple pods. An example of such a purple-podded runner bean is ‘Aeron Purple Star’.
Runner beans have also been called “Oregon lima bean”, and in Nahuatl ayocotl or in Spanish ayocote. Runner beans, like all beans, contain the toxic protein phytohaemagglutinin and thus should be cooked well before eating.
II. How to Grow and Care
Sunlight
Runner beans need full sun, meaning at least six hours of direct sunlight on most days.
Temperature and Humidity
These plants are not cold hardy and will die when the first frost arrives in the fall. In temperatures above 90 degrees Fahrenheit, bean production will slow. But it should pick up again once the weather cools. A moderate humidity level is best for the plants.
Watering
Runner beans require consistent moisture, but they never should be sitting in soggy soil. Plan to water as often as needed to keep the soil lightly moist but not waterlogged.
Soil
A loose, organically rich, loamy soil with a slightly acidic to neutral soil pH is ideal for runner beans.
Fertilizing
It’s ideal to mix a layer of compost into the soil in the fall prior to planting. Then, give your beans a side dressing of compost midway through the growing season to encourage vigorous production through fall.
Pruning
Pruning isn’t an extensive chore with runner beans. But you can pinch the tops once they’ve twined to the top of their supports. That way, they can focus their energy on producing flowers and pods rather than growing more foliage.
Propagation
Runner beans are best propagated via saved seeds. This is an inexpensive and easy way to create more plants from a variety you particularly liked. Plus, if you live in a climate where you can only grow runner beans as annuals, you’ll ensure that you have crops for the next year. Save the seeds in the summer or fall for planting the following spring. Here’s how:
- Let some seed pods fully dry and mature on the plant. They will become brittle.
- Harvest the dried seed pods, and break them open to release the seeds.
- Let the seeds thoroughly dry in a cool, dark, well-ventilated area. Then, store them in an airtight container.
How to Grow From Seed
You can direct sow or start the seeds indoors four to six weeks before you plan to move them out. Beans grow quickly and do not transplant well, but if you have a short season and want to get a head start, sow them inside in peat or paper pots. Wait until the ground has warmed before planting outside.
- Plant two to three seeds at the corner of each pyramid-like support or space seeds six inches apart along a trellis. They are quick to germinate.
- Train them along with their support to get them started. Use twine or twist ties to loosely attach early stems to the trellis.
- Once started, the tendrils and vines will begin to cling and climb on their own.
Potting and Repotting
Container growth can be a good option if you don’t have garden space. But runner beans need a fairly large container to grow well. The container must be heavy, so it can support stakes for the beans to climb. Opt for a container that’s at least 30 inches wide and 18 inches deep. The container must have drainage holes. Unglazed clay is a good material, as it will allow excess soil moisture to evaporate through its walls.
If you start your runner beans in a small pot, repot the seedlings once they’re about 3 inches high in a container that can fit their mature size. Another option is simply to start them in the large container, so you don’t have to disturb their roots with repotting.
Overwintering
If you live in an area that doesn’t get frost over the winter, you can leave your bean plant roots in the ground after the foliage depreciates. A layer of mulch can help to insulate the roots and retain soil moisture ahead of new growth in the spring.
Pests and Diseases
Runner beans don’t usually have major problems with pests or diseases. Some pests that might affect the plants include Mexican bean beetles, Japanese beetles, leafhoppers, aphids, slugs, and snails. Potential diseases include mosaic virus, blight, anthracnose, and powdery mildew.
What month you pick runner beans depends on when they were sown, but the plants will typically start producing harvestable beans around midsummer. In general, you’ll see flowering approximately four to five weeks after planting and harvestable beans approximately 60 to 75 days after planting. And you should be able to harvest until frost arrives in the fall.
You can pick pods when they’re young and tender to cook or allow them to fully mature to shell or dry. Check for harvestable beans every few days to keep the production going. The pods are ready when you can snap them cleanly from the vine.
You can store your beans in the refrigerator for about a week for cooking. For drying, set them in a single layer in a well-ventilated area to thoroughly dry, and then store them in an airtight container.
III. Uses and Benefits
Runner beans were grown as food plants in North America and Europe from the 1600s, and also as ornamentals for their attractive flowers. However, they came to be used primarily as a garden ornamental plant in North America, including for temporary screening. The flowers attract hummingbirds, bees and other insects. In the UK and other European countries – where the vegetable is a popular choice for kitchen gardens and allotments – the flowers came to be ignored, or treated as an attractive bonus to cultivating the plant for the beans.
The seeds of the plant can be used fresh or as dried beans. The pods are eaten whole while young and not yet fibrous, though they tend to have a rougher surface than the common bean. The starchy roots of this perennial are eaten in Mesoamerica.
The beans are used in many cuisines. It is a popular side vegetable in British cuisine. A variety named ‘Judión de la Granja’ producing large, white, edible beans is cultivated in San Ildefonso, Spain. It is the basis of a Segovian regional dish also named Judiones de la Granja, in which the beans are mixed with pig’s ears, pig’s trotters, and chorizo, amongst other ingredients.
In Greece, cultivars of the runner bean with white blossom and white beans are known as fasolia gigantes (φασόλια γίγαντες). They are grown under protective law in the north of Greece within the regions of Kato Nevrokopi, Florina and Kastoria. The beans have an important role in Greek cuisine, appearing in many dishes (such as Gigantes plaki). In English, they are sometimes colloquially referred to as elephant beans. In Austria the coloured versions are cultivated and served as “Käferbohnen” (“beetle-bean”), a dish made of the dry beans with pumpkin seed oil. It is considered a typical dish of regional Austrian cuisine, but dried runner beans are also consumed to a small extent in Germany. In Turkey, runner beans are the main ingredient in bean Pilaki and Piyaz.
Greece and northern Africa are the sources of pods of the runner beans sold as “green beans” in European markets during the cold period. The pods can be identified by their big size and the rougher surface.
IV. Harvesting and Storage
- Harvesting the beans encourages the production of additional flowers.
- Pick pods when young and tender, about 6-8 in. (15-20 cm) long. The pods should snap easily, and the beans inside should still be small and pale in color.
- Harvest your Runner beans regularly (every 2 or 3 days) to prevent bean pods from reaching maturity. Once this happens, the plant will stop blooming, and no more pods will form.
- Runner beans should be stored in the refrigerator and are best if used within two to three days.
