Growing beans in your vegetable garden is relatively easy and extremely rewarding. Although all the plants we cultivate today were derived from wild plants before recorded history, humans have been cultivating beans for over 4,000 years. According to the University of California, Riverside, the first old world beans cultivated were broad beans and soybeans. Other bean varieties were introduced to the new world by explorers. The common bean came to the U.S. from Central America and Mexico.
Photo: Gena Breakiron
The bean family (Fabaceae) is an extremely diverse group of plants which consists of more than 20,000 species. This group includes peas, beans, lentils, chickpeas, peanuts, and soybeans. Interestingly, it also includes clover, licorice, redbud, black locust, lupine and many other unexpected plants. These plants are called legumes.
Legumes have nodules on their roots which convert nitrogen in the air into a usable form for the plant. This takes place through a symbiotic relationship with bacteria called rhizobia, which live in the root nodules. When the plant dies and decomposes, the nitrogen is made available in the soil. This is called nitrogen fixation, and is one of the reasons some legumes are used as cover crops.
Photo: Gena Breakiron
Cultivating beans can be simple depending on what type you choose to grow. What we refer to as snap beans (Phaseolus vulgaris), or “green beans” usually alludes to the unripe fruit of the bean plant, and includes the pod and the immature seeds. Since we don’t allow these plants to ripen and dry, they are not considered legumes in the culinary sense. While we may think of green beans as vegetables, botanically speaking they are a fruit as they come from the flowering part of the plant and they contain immature seeds. They can be green or purple in color. There are many varieties of both French filet or flat romano beans. Most are available in both bush and pole types.
These plants grow quickly, most in 50 to 60 days. Since you are harvesting the unripened fruit, if you continue to harvest, the bean plant will continue to produce more beans. The plant’s main goal in life is to reproduce, so it will carry on trying to meet its goal by producing more potential seeds. If you allow the seeds to mature and dry on the plant, it will consider its goal met, and production will cease.
Not every bean can be safely eaten in its unripened state. Many have toxins which require some special preparation even when not eaten raw. Dried beans will have to be soaked in water and rinsed several times before cooking. Additionally, the beans will need to be boiled in fresh water for at least 30 minutes before consuming. Do not use a slow cooker to prepare dried beans. You can read more about this topic from Kansas State University research and extension.
Most beans and other legumes are dried on the vine. When dried, the beans, lentils, chickpeas, etc, have a longer shelf life. These are the seeds of legumes, and they are called pulses. According to the National Institute of Health (NIH), “Pulses provide protein and fibre, as well as a significant source of vitamins and minerals, such as iron, zinc, folate, and magnesium.” You can read more about pulses from the NIH using the link following this article. Pulses are inexpensive, which makes them an economical source of these nutrients.
There are three growth habits of beans. You’ll want to make sure you choose the growth habit that best suits your gardening style and infrastructure.
- Bush beans are popular due to their compact shape and rapid maturity. They usually grow 12 -24 inches tall and can easily be planted in rows without any structural support. Picking takes place close to the soil, so expect to bend over or bring a kneeling pad.
- Half-runner beans grow up to 3 feet long. Longer than bush beans, but not as long as pole beans. Trellises may improve yield, but it is not necessary.
- Pole beans may grow 6-8 feet tall. They can supply the greatest yield, but they will need a sturdy trellis. You’ll want to use a vertical structure for the beans to climb. A teepee made from branches or bamboo would work well, if you can make it sturdy enough to withstand wind and storms. Cattle panels can provide a strong structure also.
Pole beans on a cattle panel
photo: Gena BreakironScarlet runner beans are a type of pole bean that can grow up to 15 feet tall. It will, of course, need a sturdy trellis. Its abundant, vibrant red blossoms invite pollinators to your garden. Additionally, those blossoms give rise to spectacular purple beans that can be eaten unripened, as “green” beans, or left to dry on the vine and saved as pulses. Interestingly, the pods turn green when cooked! This is caused by the anthocyanins — the purple color being destroyed by the heat, leaving the green color chlorophyll.
Here are the planting instructions provided by Virginia Tech Extension:
–Seed after danger of frost is past.
SEED and ROW SPACING:
- For bush snap beans, plant seeds 2 inches apart, with rows 24 to 30 inches apart
- For bush lima beans, plant seeds 4 inches apart, with rows 18 to 30 inches apart
- For pole beans plant seeds 4 to 8 inches apart, with rows 24 to 36 inches .
Another bean you may want to try is lima beans (Phaseolus lunatus). They are available in bush and pole types. The bush beans will mature more quickly, but the pole beans will produce more beans over a longer period. Lima beans can be picked in their green state, but wait until the pod feels fat or filled out. However, don’t eat them raw! They will need to be shelled and cooked first, as they contain linamarin, a cyanogenic glycoside. Boiling the lima beans in a large amount of water and cooking them for at least 30 minutes seems to be the best way to reduce the toxin. You can read more about this from OSU Extension.
If you decide to dry them, allow them to dry on the vine. This is tricky. If you wait too long for them to dry, the shell will open, spilling the beans (seeds) on the ground. If you harvest too early, the shell may molder, along with the beans. I find that it’s best to look for shells that have just, barely begun to turn brown. The shell will feel leathery, and the beans inside will not be growing any more. Picked in this state, they will continue to dry, and you won’t lose the contents. You can dry them indoors, in a warm dry spot. Be sure to spread them out so they are a single layer. Flip them over or “stir” them every other day. A large, clean boot tray works well for this. You’ll know when they are ready to be shelled, as the shells will “pop” open. It’s very satisfying.
An interesting bean you may want to try is the “yardlong” bean (Vigna sesquipedalis). It is also sometimes referred to as, Chinese longbean, noodle bean, and pea bean. They can easily grow up to 20 inches in length, but most consumers prefer them between 10”-12”.
photo: Gena Breakiron
Red Asparagus beans (Vigna unguiculata), a purple podded variety, matures more rapidly than yardlong beans. They thrive in hot weather, attract pollinators and will continue to produce until close to the first frost. Although they resemble green snap beans, long beans are more closely related to the cowpea family (Vigna unguiculata).
Unfortunately, legume crops do have their share of pests and diseases. It’s always best to look for resistant varieties if you find diseases a problem in your garden. Remember to rotate your crops, especially if you experience any diseases.
Some common and not-so-common problems you may encounter include Mosaic virus, Anthracnose, Bacterial blight, and seed, root, and stem rots.
Mosaic virus is spread to gardens by plant-sucking insects. You can try to avoid mosaic virus and other diseases by employing some safety methods. Try to purchase only certified, disease-free seed. For mosaic virus, observe your plants frequently for insects or evidence of their presence and remove any insects you see.
Anthracnose is a fungal disease which is spread by spores. These are microscopic reproductive units which are spread by the wind. They can overwinter in the soil and on infected plant debris. They can also transfer to your plants by rain splashing infected soil onto the plants.
Bacterial Blight shows up on leaves as brown spots encircled with a yellow ring. These can enlarge and kill the leaves.
Seed, root, and stem rots are fungal diseases. To avoid seed rot, plant at the correct depth (2x the width of the seed). Do not plant in cool moist soil. Plant after the soil has warmed and be sure the soil/seed doesn’t dry out completely before germinating,
There are some cultural practices you can employ which can help you avoid, or at least limit the damage of these diseases:
Use mulch or dried, shredded leaves around the base of plants. This not only helps the roots maintain moisture, it also provides a more absorbent medium for rain, and may prevent splashing. When watering, try to water in the morning, and take care to only water at the base of the plants to avoid wetting the leaves.
Immediately remove, and dispose of any sick or damaged plants. Be sure to collect all the dead or damaged leaves that have fallen from the plant, and don’t put these in the compost! To kill fungi, viruses and bacteria, clean any tools in a 10% bleach solution. To prevent rust, be sure they are thoroughly dried and oiled before storing. For prevention, make plans to rotate your crops every year. Maintaining accurate records or keeping a garden journal can help with this task.
In addition to diseases, there are a few pests that may make an appearance in your bean patch. The Mexican bean beetle and its larva would likely be the most obvious culprit. You’ll probably notice these yellow, fuzzy troublemakers in their pupal or larval stage. I check frequently and squish them. More importantly, if you find yellow eggs, you can remove them before they can do damage. Here is a great article by fellow Master Gardener, Cleve Campbell which you’ll want to read if you plan to plant beans. Also, keep an eye out for aphids. In addition to the damage these sap-sucking insects can cause, they also carry diseases from plant to plant.
If you have questions or need advice, you can always contact the Piedmont Master Gardeners-Horticultural Help Desk.
Any bean you care to eat can be grown in your garden. Purchase seeds from a reputable seed company or learn how to save your own seeds. The instructions for harvesting dried legumes are the same as for the lima beans. It is very rewarding to feed your family from your own garden. However, take some time to think about how you want to spend your time. Growing beans or other legumes for drying is very time consuming. To harvest them at the ideal time, requires frequent inspection and many trips to the garden. Because the cost of dried beans is rather low, you may choose not to grow them. It’s a personal choice only you can make. Many gardeners feel the time commitment is worth the satisfaction of providing their families with high quality, clean food. It’s especially important when you know you can produce a superior product, with no chemicals.
Take a chance. Try something new in your garden. Whatever you choose to plant, you’ll learn something from the experience. You may learn the new plant is not for you, or you may find a new favorite crop! Either way, Happy Gardening!
Featured Photo: Gena Breakiron
Sources
Food History-University of California, Riverside
NIH-National Library of Medicine-Pulses nutritional information.
Kansas State University research and extension-safely cooking beans
North Dakota University- bean nutrition
The Mexican Bean Beetle, by Cleve Campbell