Don’t Know Beans?
By Glenn I. Teves, UH County Extension Agent
Legumes or beans are high in protein, and called the meat substitute of the plant family, but what makes them unique from meat is their high water and fiber content that fills us up, and we don’t get enough fiber in our diets. The recommended weekly dietary intake of beans was recently increased three-fold to three cups a week! Of 100 foods measured for their antioxidant capacity, three beans made the top four: azuki, kidney and pinto beans.
Native to the tropics and members of the Leguminosae family, types of beans are endless including limas, wing beans, soybeans, snap or green beans, and even peas. Many are fairly easy to grow, and are favorites on Molokai, including long bean, cowpeas and pigeon peas.
Drought-tolerant varieties include pigeon pea, cow pea, long bean, wing bean and lima, and these will thrive in the dog days of summer. There are many plant types, including vines and bushes. Some are even nematode-resistant, including Iron and Clay cowpeas, and University of Hawaii selections Kailua and Kahala soybean, as well as Manoa Wonder and Poamoho pole bean.
Legumes are unique in the plant world because bacteria called Rhizobia will attach to the roots and grab nitrogen, an important nutrient for plant growth, from the air. Thus, they require less nitrogen fertilizer for optimal growth.
For those with limited yard area, vine types work best, but it comes down to which you like to eat and how much effort you’re willing to put into growing them. Some, such as pole beans, require care and protection from some insects, while wing beans and limas are relatively low maintenance.
Most legumes are fairly tolerant of pests. The worst pest of beans — especially the more tender types — is the French bean fly. A tiny fly, it will lay its eggs in the stems of beans near the base and affect the uptake of nutrients and water. Under extreme conditions, the stem will break. The recommended strategy is to impose a crop-free period, with no beans in the area for a month or two before planting again. French bean flies don’t appear to affect pigeon pea and wing bean, and possibly others, so avoidance is another strategy.
Some pests will zero in on certain types of beans, such as rose beetles and mites on long beans, green or snap beans and soybeans. There’s also a small purplish butterfly called a Lycaenid whose caterpillar will chew on young bean pods. Bean pod borers will attack dried beans on the plants, so pick beans before they get too dry and store them in diatomaceous earth, a food-grade additive made of coral creatures called diatoms.
Legumes do better during summer months because many are considered long-day plants, especially soy beans and long beans. Green beans and peas thrive in the cooler months. Bush green beans favorites include the flat-podded Green Crop and Bush Kentucky Wonder, and the round podded Blue Lake types. Many edible podded pea varieties do well here, including Manoa Sugar and Oregon Sugar Pod II.
Many other types of beans used for dried beans, such as navy, kidney, pinto, garbanzo, mung, adzuki, and others, are not commonly grown in Hawaii, but can be. They key is to protect them from rodents, birds, and bean pod borers since they will need to be held in the field longer than green types.
There are a bunch of publications on beans at the UH CTAHR website. Just punch in “beans” or “peas” at ctahr.hawaii.edu/site/Info.aspx.