The Mung bean, scientific name Vigna radiata, is commonly grown as a sprout.
Other common names for the Mung Bean plant include Golden Gram, Green Gram, Wild Mung, and Mash Bean.
Close up of Vigna radiata leaves and flower, photograph by Dinesh Valke; CC.
Mung bean sprouts can be grown both indoors at home and outside.
As well as growing mung beans as sprouts (see later section), they can also be planted out in the garden.
Late spring, when soils are warm, is the best time for planting, and beans should be able to be harvested in as little as three months (typically 100 days).
Mung bean seeds are usually green or brown, but some tropical varieties are yellow, and they are normally half the diameter of a soybean (Glycine max) seed.
The appearance of mung bean plants is more similar to garden beans than it is to soybeans. They can grow up to 24 to 30 inches (60 – 75 cm) tall; they also have smaller leaves than soybeans, and a moderate number of branches.
Pods are three to four inches long, with 10 to 15 seeds each, and there are 30 to 40 pods in every plant.
The color of the pods turns darker as they mature, making it easy for growers to known when harvesting time is nearing.
There are a few varieties of Mung beans available. These varieties include Berken – green-coloured seeds, and preferred by many buyers – and Texsprout, which produces larger seeds than Berken.
Mung Bean Sprouts by Crispin Semmens.
If you are sprouting mung beans for culinary use then follow this simple procedure:
You will see small sprouts after about two days. If you prefer longer sprouts it will take about five days.
Mung Bean Sprouting, image by Thamizhpparithi Maari; CC.
Proper soil preparation should be conducted when growing mung beans. It is best to conduct planting in the spring after the last frost passes.
The soil should be broken with the use of a garden spade to a depth of at least six inches.
Sprinkle two inches of compost on the top of the soil, and then rake the soil smooth.
Although mung beans are easier to plant than many other bean crops, an ample amount of soil preparation is beneficial.
The ideal season for mung beans to be planted in most northern hemisphere locations is late May and mid-June, when the weather is not too cold, not too warm, and the last chance of frost has passed.
However, in other parts of the globe, such as in Asia, mung beans should to be planted in mid-November, after the rainy season has passed.
For indoor planting, it is essential to use a container that has a drainage hole in the bottom, as mung beans plants will drown when soaked in too much water.
A large clay pot, wooden barrel or other similar container serves well.
Place at least three to five inches (7–12 cm) of soil in the container and make sure that the soil has a neutral pH, from 6.2 to 7.2, to promote healthy sprout growth.
Water the newly planted beans to provide preliminary moisture for germination. Do not overwater as Mung beans will not do well on oversaturated and soggy soil.
Cover the container with a lid, such as a plastic garbage can lid, newspaper, or planter bottom. This will help keep the soil and seeds slightly moist, and will promote the development of sprouts.
Mung Beans sprouts should be seen after about a week; the warmer the temperature, the faster the seed germination.
Place the seedlings in a sunny location to encourage faster growth. It is not advisable for the plants to be watered frequently; wait until the soil becomes dry before watering.
Mung bean plant, photograph by Dinesh Valke; CC.
For outdoor planting, the recommended seeding rate is 15 pounds per acre for wide rows. The soil should have a pH of 6.2 to 7.2, and seedlings sown in a sunny location.
Seeds can be planted directly in rows, at a depth of 1 inch (2.5 cm), spaced at 2 to 4 inches (5–10 cm) apart, and with 30 to 36 inches (75–90 cm) between rows.
The pre-sprouting of seeds before sowing is advisable; this can be achieved by soaking the beans in water for 24 hours.
Next, drain and leave them for another 24 hours until tiny roots start to poke out. Germinated seeds should then be planted straight away to avoid them drying out.
Sow the germinated beans into compost that is about two to three inches deep (5–8 cm), and place tray lids/or other cover over them to keep them warmer during the night.
Seedlings should be seen after about two weeks.
Always make sure that the plant-bed is free from weeds, and supply water when required. Do not overwater the plant, as they are susceptible to drowning.
Mung beans do best in a light to medium rich soil, although legumes can fix their own nitrogen, you may need to supply a low nitrogen 5-10-5 fertilizer of the soil is poor.
The mung bean plant secretes a sticky sweet substance that attracts several kinds of insects. Aphids, mosquitoes, cucumber beetles, and many types of worm are attracted, but can be easily controlled using a mild dose of organic the insecticide pyrethrins.
Mung beans start to form once plants reach a height of 15 to 18 inches (38–45 cm), and are typically ready for harvesting 100 days after sowing.
The beans will not mature at the same time, so harvest when about 60% of pods have reached maturity.
Collect the whole plant, tie into bunches, and then hang upside down to dry out over a large sheet of paper.
Once dried it is easy to shell the beans.
For large scale Mung Bean growth, the success or failure of the crop is often determined in the management and harvesting conditions.
As the pods of mung beans are brittle and thin when dry, shattering can be a problem during harvest.
To reduce seed shattering, the preferred harvest method is direct combining which requires plant to defoliate and dry down in a timely manner.
Mung beans planted in May normally dry down and defoliate in September.
The dry seeds can be stored in a glass container for many years, and the viability can be improved by freezing the mung bean seeds, as this destroys insect infestation.
Mung Bean Pods by Mike Fernwood.
They are rich in bioavailable vitamins, minerals, proteins, amino acids, phytochemicals and energy; such nutrients are vital for human health, and have led to mung beans becoming part of many cuisines.