You’ve probably met members of the huge Family Fabaceae in a sunny meadow or climbing a fence post in the springtime—clovers and sweet pea are everywhere, but so are their edible cousins, the legumes. Legumes are popular bases for a vast number of dishes belonging to cultures from around the world. In parts of America, the green bean is one of the best represented members of this family, but these immature bush beans are grown out in other areas and dried.
Besides their culinary flexibility, legumes are really special because of their ability to fix nitrogen from the environment. See, legumes have a long-standing symbiotic relationship with certain families of bacteria that live inside the nodes that form in a legume plant’s root system. As these bacteria live and grow, they excrete excess nitrogen, making it available to the plant that protects them. Because of this, legumes can often grow in extremely poor soil, but the ability to fix nitrogen varies from variety to variety.
So many legumes, so little time
The groups listed below represent the main types of legumes; there wouldn’t be room to list every specific type within these groupings. There are literally thousands of types of beans alone, making for one vastly important horticultural grouping of plants. Many of these legumes have special growing requirements or need very long growing seasons, but they do extremely well in containers, so give them a shot in your greenhouse. Many legume seeds last as long as five years, allowing you plenty of time to try a healthy selection.
I look forward to growing bush beans every year. My family loves them and I get a weird delight out of running up and down the rows of fat, tender pods and picking them by the handful. We mix the purple, yellow and green snap beans to create an early-season garden of color and cook them altogether in one big pot. Beans have a way of giving a gardener a very strong sense of success, and as long as you don’t plant them too closely, many members are basically guaranteed to succeed.
Bush beans – Sow seeds 1 inch deep, spaced two inches apart with the soil warmed to between 60 and 80 degrees Fahrenheit (15 to 26 degrees Celsius). Seeds will emerge in 8 to 10 days. If you intend to transplant your seedlings, plant them in biodegradable pots; beans do not like to be moved.
Garbanzo beans – Garbanzos require a very long growing season, typically 90 to 100 days, so starting them well before time to transplant is recommended. Sow seeds 1 1/2 to 2 inches deep in soil warmed to between 60 and 80 degrees Fahrenheit (15 to 26 degrees Celsius) and they’ll germinate in 10 to 14 days. Leave the pods to dry on the plant for dried beans.
Lentils – Lentils also need a very long growing season, 80 to 110 days, so start them indoors in biodegradable pots. Warm the soil to about 68 degrees Fahrenheit (20 degrees Celsius) and plant your seeds up to 1 inch deep. Your seedlings will emerge in about 10 days.
Lima beans – Limas grow much like bush beans, so warm your soil to between 60 and 80 degrees Fahrenheit (15 to 26 degrees Celsius) before starting your seeds indoors. Push the seeds up to 1 1/ 2 inches deep and water them well; seedlings with sprout in 4 to 7 days. Wait to transplant outside until at least two weeks after all danger of frost has passed.
Peas – If you’re a beginning grower, peas are one of the best places to start—they’re so easy a child can grow them (and should). Start your peas indoors at a temperature between 50 and 85 degrees Fahrenheit (10 to 29 degrees Celsius), 1 to 2 inches deep. They germinate in 9 to 13 days. Peas will do well in deep, wide pots and trained up a tower, or as transplants when potted in biodegradable pots or cells.
Peanuts – Several legumes require long growing seasons, but none rival the peanut, so plan way ahead for their up to about 140 days to harvest. Start seeds in your greenhouse in biodegradable pots warmed to between 68 and 95 degrees Fahrenheit (20 to 35 degrees Celsius). Push the seeds 2 to 3 inches under the soil’s surface and wait about 10 days for emergence. When you transplant your seedlings, do so into soft, sandy soil—peanuts are one of the few plants that flowers above ground, but fruits below it. If the flowers can’t bury themselves in the ground, you won’t get a good crop.
Pole Beans – Pole beans grow very much like bush beans, in fact, they’re the same species! Like bush beans, if you want to start pole beans inside, make sure you do so in biodegradable pots because they can’t bear to have their root systems upset during transplantation. Plant your seeds about 1 inch below the soil line once soil has been warmed to between 60 and 80 degrees Fahrenheit (15 to 26 degrees Celsius). You’ll have seedlings in a little over a week.
Scarlet Runner Beans – If ever a bean added color and flavor to the garden, it’s the scarlet runner. Start these beans indoors, two to three weeks before the last frost (they grow fast). Sow seeds about 1 inch below the surface of soil warmed to between 60 and 70 degrees Fahrenheit (15 to 21 degrees Fahrenheit). They’ll emerge in 4 to 7 days.
Soybeans – Soybeans are an uncommon garden vegetable, but if you’d like to try them, there’s no reason not to: they’re delicious, nutritious and easy to grow. Warm your soil to about 65 degrees Fahrenheit (18 degrees Celsius) for best germination and push the seeds 1 to 2 inches into each cell or pot. Seedlings emerge in about a week, but harvests tend to be all at once, so plant successive seedlings if you want a prolonged soybean season.
Winged Beans – Winged beans, also known as asparagus peas, are an unusual legume occasionally grown in home gardens. They can be incredibly hard to start, due to low germination rates and a particularly tough seed coat, but don’t give up if you don’t succeed right away. Nick seed coats and soak them for up to two days before planting to increase the chances of successful germination. Warm the soil in your biodegradable pots to around 70 degrees Fahrenheit (21 degrees Celsius), then plant your seeds 1 inch below the soil’s surface. Seeds will germinate in 10 to 14, if they’re going to—make sure you plant at least twice as many seeds as you think you’ll need.