An ancient crop of Asia, mung beans produce clusters of long slender pods that contain small seeds. These plants grow between 18- to 36-inches tall. Gardeners often harvest this plant at a very early stage of growth, before it matures into a large plant. Grown for sprouts, mung beans provide a useful ingredient in many Asian recipes, as well as a component in various types of salads and sandwiches. Like many other types of seeds, mung beans require specific conditions to germinate and sprout.
While some seeds require light to germinate and begin sprouting, several types of beans, including mung beans require darkness to germinate. Outdoor planting in sunny areas requires a depth of at least 1 inch to block light rays during the period of germination. Plant them about half an inch deeper in sandy types of soil. Beans germinated for use as sprouts must also receive a period of darkness. Placing them in a dark container and covering the top of the container with dark paper can help protect them from excessive amounts of light.
Mung beans require moisture to soften the seed coat and begin the germination process. Soaking mung beans for a few hours before planting allows the seed to swell and begin softening prior to planting. Ensure adequate moisture by pre-irrigating your soil before planting your mung beans. Keep the soil evenly moist while the beans begin to sprout.
Mung beans are one of many warm-season food crops. Warm-season crops require soil temperatures above 55 to 60 degrees Fahrenheit to begin sprouting. In cooler climates, starting these beans indoors allows sufficient time for the seeds to germinate and grow to maturity before freezing temperatures arrive in the late fall.
Like other types of seeds, mung beans contain small life-support systems that provide the initial nutrition for early growth. However, once the seed begins to sprout and deplete this small storage of nutrients, it requires suitable soil to encourage continued growth. Mung bean sprouts prefer soils with pH levels between 6.2 and 7.2, as well as adequate amounts of sulfur, magnesium phosphorus and potassium. Fertile soils that contain a rich blend of sand and loam provide essential nutrients for healthy growth.