The Scarlet Runner bean is a plant that blurs the line between ornamental and edible. In the US, the seeds are most often found in the flower section, while in the UK they are a very popular edible bean. Originating in Central America, Phaseolus coccineus was used by the Aztecs as a primary food source. Also known as Oregon lima beans, they are easier to grow in our short summers than limas, requiring less heat than limas, but they substitute just fine for them in recipes.
The long vines – they can grow up to 10’ tall- bear trusses of brilliant red flowers that are hummingbird magnets. They make a good, fast growing screen- my first experience with them was as a child when my mother planted them below the front porch for a privacy screen. Despite being on the north side of the house, they quickly grew up to the top of the porch and gave a lovely show- and did the job of giving us a private spot to read on the porch. Perennials in the far south, the fleshy, starchy roots are edible, as are the leaves and, of course, the beans. They beans are delicious as green beans; the broad, flat, hairy pods have an intense bean flavor rather like Romano beans on steroids. They can also be used as green shell beans, or dried shell beans. The dried beans are even lovely to look at; they are large, black beans with pink spots. One caveat is that you shouldn’t eat the shelled beans raw (or any other shelled beans); the mature beans have a toxin in them that is inactivated by cooking. Kidney beans actually have the highest amount of this toxin.
Scarlet Runner beans take about 61 to 70 days to produce. If you plant them too early while the soil is cold they will just sit there- or possibly rot- but once the soil is warm they will climb quickly. You won’t gain much by starting seeds indoors and transplanting them; this year I started some inside and directed seeded some outside later and both sets of plants are at the same stage of development. Like all beans, Scarlet Runners prefer full sun. Plant after the last frost; soaking the seeds for a couple of hours or even over night will speed germination. Plant in soil enriched with compost and give a fertilizer high in phosphorus, and keep well watered; the flowers will fall off if the plants get hot and dry. Give them something to climb; if left on their own the plants will grow into a big tangled ball on the ground.
For green snap beans, harvest when the pods are less than 6” long; any larger and the pods get too stringy. For green shell beans, let the pods swell up and get all lumpy. Zip your thumbnail up the side of the pod to open it and extract the beans. For dried beans you want to leave the pods on the vine as long as possible. Stop watering them near the end of August to speed drying. The vine will stop flowering as they dry. Any pods that have no ‘bulges’ go ahead and pick for snap bean use; they won’t have time to develop seeds and dry. Allow the bulgy beans to stay on until the leaves start to die, then pick and bring in the pods. If we are having a rainy autumn and the pods start to get moldy, pick and bring them in immediately. Shuck the beans out of the pods as soon as you bring them in to speed drying. Be gentle; the skins on the beans is very tender at this stage. Spread the beans out on a cookie sheet covered with a couple of layers of newspaper. Shake the pan gently every couple of days to roll the beans so all surfaces dry. It’ll take a week or more for them to dry enough for storage, depending on the heat and humidity in your house. Store in jar in a cool, dry place. If you have any, place a packet of desiccant in the jar with the beans (frequently found in jars of vitamins)- be sure to remember to remove it when you go to cook the beans! Soak the dried beans for a few hours before cooking, and pour the soaking water off. Refill the pot with fresh water for cooking them for several hours.