Have you ever heard this term before? I thought not. That's the current, though obscure, family name for what many readers already know as legumes. The legume family is enormous and spans the globe. It includes some trees and many ornamental and food plants. In the average backyard garden, legume means green beans and spring peas. To the more curious gardener, legumes include many unique beans to flirt with in the kitchen. Hummingbirds love the flowers of some tall legumes.
Easy to grow and nutritious, beans and peas are standard fare for many American home gardens. Like any self respecting vegetable, fresh legumes can contribute an array of nutrients to your recommended daily intake. Fresh beans and peas are not earning "superfood" gold medals, but don't pass them by. A cup of green beans gives you about 30 percent of the vitamin C you need daily, for example1. Beans and peas are super easy to plant and use. Let's find the right legume for your garden.
Easy peasey (and beansey,) legumes are among the easiest vegetable crops
Relatively large seeds make beans and peas easy to plant. Plant them an inch or so deep, and watch the sturdy seedlings unfurl from the soil surface days later. Unique root biology makes legumes less needy of highly fertile soil. Like most vegetables, legumes grow best in full sun and neutral soil. Beans and peas grow quickly. Best planting dates will vary by type of bean and garden location. Some legumes can take a bit of chill. Others need warm soil and sunny days to produce a crop.
The part we eat as a vegetable is an immature seed pod, or barely mature seeds. If left on the plant too long, most peas and beans become starchy. Those starchy beans can be shelled, cooked and eaten just like dried beans you've used in soup. One caution: mature beans of some legumes have toxins. Kidney and lima beans, for example, must always be boiled before being eaten. This rule also applies to some novelty tropical beans too. So while you may freely eat English peas and standard young green beans right off the plant, use caution with other bean varieties. Do not start grazing on other legumes unless you have determined that they are not toxic. Ornamental sweet peas for example, have toxins. Please refer to "Beans! Beans! The Poisonous Fruit! by Lois Tilton for detailed information on bean toxins.
Cool weather legumes: English peas, sugar snap peas, snow peas
These chill tolerant types can be planted in early spring. Aim for six to eight weeks before your last frost date. Peas will need a light fence to climb. Some gardeners use long trimmings from shrubs as "pea brush." Stick branches in ground alongside the peas as a temporary support. Spring pea crops may be finished by early summer. Consider following the peas with a warm season crop such as cucumbers. Also consider picking some young tender pea leaves and blooms to add to your green salad.
Hot weather legumes: green (string) beans, lima beans, cream peas, field peas
Plant these after the last frost date. Many varieties and hybrids of green beans (snap or string beans) are in cultivation. Gardeners may choose beans by size, shape, color and most importantly by growth habit. A bush bean grows a plant about knee high for easy picking, with many beans maturing in a short time span. Pole beans make vigorous vines that need to climb up a string or pole. Native American gardeners used living cornstalks as bean poles, making for a very productive garden. Pole beans usually produce more beans than bush types overall. Lima beans can be either bush or pole type as well. Limas take longer to grow so are less used in northern gardens.
Southern gardeners have long enjoyed cream peas, crowder peas, and various "southern" peas. Some northern gardeners can grow them, too. These are hot weather grown beans. Plant them in well-warmed soil, a month after the last frost date. The pods grow until well filled, and then the beans or peas inside are shelled out and cooked. Southern Living offers more insight into various field peas from the kitchen perspective.
Adventurous garden catalogs offer excursions into the land of unusual legumes.
- Peanuts are legumes. Grow peanuts at least once, to witness their strange way of forming fruits. Peanuts need warm soil and a long season.
- Scarlet Runner beans are often grown for their beautiful flowers. Their large beans and flowers are tasty, too. They grow a climbing vine, and cannot tolerate hot weather.
- Fava beans (broad beans) are not well known in the United States. Favas must be planted in cool seasons and will not set pods in warm weather. Plant favas very early in spring. They'll grow to a sturdy three foot plant.
- Yard-long beans (asparagus beans) are an African original and Asian favorite. They grow like pole beans, producing tender, skinny long beans from pretty flowers.
- Edamame (edible soybeans) are grown to eat while the bean is fresh and tender. The surprising fuzzy pods are blanched in salted water. Then the nutty seeds pop out to use as a snack or vegetable. Research continues on the possible benefits or risks of soy consumption.2
- Hyacinth beans are usually grown in America for their beautiful purple flowers and pods, but the young pods are edible,3 and well known to Indian and Asian cooks.
Care tips for legume crops
- Space plants according to packet instructions. Proper spacing reduces leaf diseases and maximizes yield.
- Use of "bean and pea inoculant" at planting time may help that unique legume root biology work to best effect. Read "To inoculate, or not to inoculate?" by Darius Van d'Rhys.
- Water the soil under, not the leaves of, bean plants. Don't work in the bean patch if the leaves are wet or dewey.
- Watch for spider mites, bean beetles, and other insects. Handpick big bugs like bean beetles, and use a general vegetable garden insecticide if bugs' sheer numbers overwhelm you.
- Rotate the location of legume planting, like you do with all other vegetables. Legumes help enrich the soil as they grow; rotation avoids a buildup of any particular disease.
Footnotes and resourcesBeans and Peas, James R. Myers, W. Michael Colt, and Marilyn A. Swanson, http://www.cals.uidaho.edu/edcomm/pdf/PNW/PNW0495.pdf
2. WebMD, Edamame (SOY) Side Effects & Safety, http://www.webmd.com/vitamins-supplements/ingredientmono-975-Edamame%20%28SOY%29.aspx?activeIngredientId=975&activeIngredientName=Edamame%20%28SOY%29
3. Lost Crops of Africa:Volume II: Vegetables, http://books.nap.edu/openbook.php?record_id=11763&page=191