Beans

Beans, beans, the magical fruit.
The more you eat, the more you…well, you know.

What you may not know about this nutritional powerhouse is that it is crazy easy to grow, germinates at lightening speed, adds nitrogen to the soil, and is just plain fun to watch grow.

Purple pole beans are easy to find among the greenery

Beans are the edible seeds of the legume family. Often, but not always, these seeds are kidney-shaped. There are over 40,000 different type of beans found in the world. Some of the more common varieties are:
​

• Vicia faba - fava beans
• Phaseolus lunatus - lima beans
• Phaseolus vulgaris - common beans, including black, pinto, kidney, green, and (my favorite) purple beans
• Vigna angularis - adzuki (or red mung) beans
• Vigna radiata - mung beans
• Vigna unguiculata - black-eyed pea
• Cider arietinum - chickpea or garbanzo bean
• Pisa sativum - peas
• Lens culinaris - lentils
• Glycine max - soybean
• Cajans cajan - pigeon pea
• Arches hypogaea - peanuts

How to grow beans

Growing most beans is really simple. Seeds can be planted 1/2 to 4 inches below soil level, watered a little at first, and then only occasionally afterward. Under ideal conditions, some beans can germinate within just 4 days, making them an excellent crop for children. Beans are not very competitive plants, so you can help your bean plants thrive by regularly weeding the area until they are firmly established. Because beans grow so fast, they can be a fun window sill garden addition. ​

Bean seedling

If you have heavy clay soil, be sure you do not overwater. Clay soil can hold so much water that plants will rot or drown. Now, if you want to get really fancy, you can inoculate the seeds with a species-specific Rhizobium bacteria. This does not mean giving tiny shots to each and every seed (But it’s a funny image, right?) Beans can be dusted with, rolled in, or briefly soaked in the inoculant at planting time to help them get the most nitrogen out of the soil, for a better start. Personally, I’ve never used inoculants, but many gardeners and most farmers swear by them, especially in areas where beans have not been grown for a long time.

Bean growth habits

Generally, bean plants come in one of two growth habits: bush (determinate) or vine/pole (indeterminate). As with other crops, determinate types tend to flower and develop pods within a set time frame, whereas indeterminate types tend to continue on for longer periods of time, producing pods as they grow. Beans prefer plenty of sunlight, but they can be grown in partial shade, as well.

​​Nitrogen boosting beans

Many orchardists plant beans and other legumes among fruit trees as cover crops to improve soil structure and add nitrogen to the soil. You can do the same thing by intercropping beans with other garden crops. Adding beans to your garden or landscape can help fix atmospheric nitrogen into the soil, making it available to other plants (assuming you cut your beans down and let them decompose before they go to seed. 

​Cowpea roots are pretty tough and deep, so they can also help improve soil structure and reduce compaction. Beans are also part of the Three Sisters method of growing used by Native Americans. The Three Sisters Method intercrops corn, squash, and beans to make the most of available growing space, soil nutrients, and water resources. The corn grows tall, the beans climb the corn, and the squash shades the ground and reduces weed competition with wide leaves.

Fava beans grow tall!

Beans and crop rotation

If you grow beans regularly, it is a good idea to rotate the bean crop with sunflowers, tomatoes, or wheat, to interrupt the life cycle of some fungal pests, such as bean rust. Bean seedlings are susceptible to damping-off disease. UC Davis provides this extensive list of bean diseases:

• alfalfa mosaic
• ascochyta blight
• ashy stem blight
• bacterial brown spot
• bean anthracnose
• bean common mosaic
• bean yellow mosaic
• common bacterial blight
• cucumber mosaic
• curly top​
• Fusarium wilt
• halo blight
• pythium wilt
• root rots
• southern blight
• white mold

​Aphids, armyworms, cucumber beetles, cutworms, darkling beetles, leafhoppers, leaf miners, loopers, lygus bugs, spider mites, stink bugs, thrips, weevils, whiteflies, and wireworms are all attracted to bean plants. The corn maggot larvae (Delia platura) and some caterpillars may also gnaw on your planted beans, as well. It’s amazing we get any beans at all, with a list like that! The truth is, bean plants are very productive and these potential problems are all relatively manageable.

Bacterial brown spot on bean leaves (Howard F. Schwartz, Colorado State University, Bugwood.org) CC BY-SA 3.0

Bean leaves infected with curly top (Howard F. Schwartz, Colorado State University, Bugwood.org) CC BY-SA 3.0

Bean seed sources

As tempting as it may be to plant beans that were bought at your local grocery store, this is a bad idea. Those beans can carry diseases that you may never be able to get out of your soil, once they arrive. These diseases are not harmful when eaten by people, but they can be devastating to baby bean plants. Instead, invest in certified bean seed, and then save seed from your harvest for next year’s planting!

Nutritious beans

As a food, beans are high in protein, fiber, iron, potassium, thiamine, vitamin B6, and folic acid, with no cholesterol. Wikipedia has an excellent graphic that shows the protein, finer, and iron content of various beans. [Spoiler alert - lentils and kidney beans top the chart!]

And if you want to avoid the undesirable side effects of eating beans, be sure to change the water a few times during soaking and/or cooking.

Finally, according to the Smithsonian, kidney bean leaves can be used to trap bedbugs!

Now you know.