Native to India where it remains a widely grown crop, mung beans grow best in a hot dry environment. For this reason, Oklahoma is the biggest producer in the United States. However, 75 percent of mung beans consumed in the U.S. are imported. The beans are drought tolerant and heat tolerant, making them one of the few legumes with these qualities grown in the United States. The U.S. boasts success with cool season legumes like chickpeas, lentils and faba beans.
Plant mung beans at the start of June in most areas of the country. They take as long as 60 days before flowers appear, and then bloom for several weeks prior to producing seed pods. As the middle of September approaches, the leaves dry up and become brown -- they may fall from the plant; at this time the plant is ready to harvest.
Like all legumes, mung beans are the seeds of the plant and grow inside pods. The pods are 3 to 4 inches long and may hold as many as 15 seeds, or beans. The plant itself is tall, as much as 30 inches, and the pods are grouped in the leaf axles, with each producing axle having several pods, and a plant producing as many as 40 seed pods per season. Although they start out green and much like garden beans, as they mature the pod darkens in color.
It is easy to grow your own mung sprouts from the beans by washing and soaking them in water overnight. Use 1 1/3 cups of beans, place them in a large jar and cover them with water. Drain off the water the following morning and rinse the beans well. Repeat this procedure every 12 hours for three to five days, depending on how large you want the sprouts. Larger sprouts may take on a bitter flavor. Store them in the refrigerator for up to two days, but beware that while their growth is slowed, it is not arrested. Use the bean sprouts raw in salads or sandwiches, or cook them in stir fries, to name a few possibilities.