When the first Europeans came to the Americas, they found Native Americans planting three vegetables in close proximity to one another. According Iroquois legend, these three species were placed on earth by the Great Spirit, and watched over by three sister spirits who are fond of one another and like to live near each other.
The vegetables, referred to by Native Americans as the "three sisters," were corn, winter squash and climbing (pole) beans. The climbing beans were allowed to twine up the stalks of corn, while the squash vined on the ground surrounding the other two. The success of this type of production known as companion planting caused these three vegetables to become mainstays in the diets of early Native Americans as well as commodities they used in trade.
Since 2021 has been declared the "Year of the Bean" by the National Garden Bureau, it is appropriate to take a closer look at this member of the triad.
Simply put, no home garden should be without beans. They are one of the easiest vegetables to grow and provide a good return for the effort involved to produce them. As a food, beans are a good source of dietary fiber, protein, vitamins and other essential nutrients.
Somewhat of a generic term, "bean" can refer to the dry seeds or green pods of a number of species belonging to various genera in the Fabaceae (legume) plant family. As legumes, beans have a symbiotic relationship with soil bacteria that are able to fix atmospheric nitrogen and convert it into a form suitable for plant use.
Horticulturally speaking, bean usually refers to various members of the genus Phaseolus, including P. vulgaris (common or garden bean), P. lutanus (lima or butter bean) and P.coccineus (scarlet runner bean). All are thought to have originated in Mesoamerica and have been used as a food source for thousands of years. The oldest-known domesticated beans in the Americas were found in a cave Peru, and dated to around 2000 B.C.
Common (garden) bean was first grown for its edible dry seeds which are high in protein. Its ease of storage made dried beans an important staple for Native Americans and New World settlers alike. Among the classes of dry bears are navy bean, kidney bean, black bean, pinto bean and cranberry bean.
For centuries, the immature pods of garden beans were not consumed because of fibrous "strings" they contained along their seams. It was not until late in the 19th century that the first stringless bean was introduced to the gardening public. This helped to spawn the use of the terms green and snap when describing garden bean. Today, garden bean comes in a variety of tastes, pod shapes, sizes and colors-all selected to be stringless.
As alluded to above, the first beans were indeterminate, vining types. Today, bush-types with a determinate growth habit dominate the market because of their ease of culture. Bush-types grow to a height of only about 24 inches and need no extra support. Since bush-types have a harvest period of about two to three weeks, succession planting is needed for a supply of fresh green beans throughout the summer into early fall.
Lima bean is another ancient bean that has been used as a food source for millennia. Given it has been used for such a long time, its exact point of origin is impossible to determine. However, researchers of the subject consider Guatemala to be a strong possibility. Lima beans are consumed as immature seeds shelled from their pods before they dry. Available in both climbing and bush types, the bush types are best suited for most gardens. Varieties with smaller seeds often are referred to as baby limas.
Some beans can be ornamental as well as edible. Scarlet runner bean is a good example of the latter. It bears attractive, bright-red flowers on vines that grow to 12 feet or more in length. Its immature pods may be eaten, or the pods can be allowed to mature for dry beans. However, unlike garden bean and lima bean, it is slow to mature. Normally, it requires 120 days for this bean to reach full maturity, compared with only 45 to 60 days for garden bean and 60 to 90 days for lima bean.
Minor species of bean include edamame (Glycine max), broad or fava bean (Vicia faba), tepary bean (Phaseolus acutifolius) and cowpea (Vigna unguiculata). Of the four, only tepary bean is native to the Americas.
Whatever the type, beans are warm-season vegetables that should not be planted until soil temperatures approach 70°F. They require a location that receives at least six to eight hours of direct sunlight and garden soil with good drainage in order to thrive. Plant bean seeds about one inch deep and two inches apart directly into the garden. After seeds germinate, thin seedlings to about four inches apart. Normally, rows are separated by 30 to 36 inches, depending on garden size.
Beans are not heavy feeders. The addition of a fertilizer high in phosphorus and potassium (e.g., 5-10-10) at the rate of two to three pounds per 100 square feet is recommended. As mentioned previously, they are legumes and can fix atmospheric nitrogen with the help of symbiotic bacteria. In locations where beans have not been grown recently, it is beneficial to add an inoculant to the soil to assure adequate microbial populations. Most outlets that sell bean seeds also sell legume inoculants.
Major insect pests of beans include bean leaf beetle and Mexican bean beetle which can be controlled with applications of carbaryl (e,g, Sevin®). Additionally, aphids, thrips and two-spotted spider mite can become problematic.
Fungal diseases of bean include anthracnose, white mold, bean rust, and aerial pythium. Good sanitation practices as well as proper planting distance and air movement can help lessen the severity of these diseases. Fungicides are seldom warranted for most home gardeners.
Green beans can be harvested when the immature pod is large enough to "snap." This normally occurs when pods are the diameter of a pencil. Pods too young to harvest will bend instead of snapping. After harvest, green beans will remain fresh for about a week when placed in a plastic bag and stored in a refrigerator.
REVISED: May 19, 2021