Did you know that the bean sprouts in your much-loved Chinese takeout derive from the mung bean seed?
Raw or cooked, eaten as sprouts or enjoyed as mature beans, mung beans have been enjoyed throughout the world for millennia, and they’re super easy to grow yourself!
Whatever your preference for growing this versatile bean, I’ll lend you a helping hand with my recommendations for the best seed sources and varieties plus planting and sprouting guides, care tips, and more.
Mung Beans at a Glance
Popular Mung Bean Varieties
The widely-recognized variety of mung bean – known as green gram – grows to an average height of 3 feet and has olive-green seeds which grow in pods at the top of the plant.
These are normally favored for their even ripening, prolific production, and lower tendency for the pods to splinter.
Other wild and cultivated mung bean types vary in height, pod appearance, and growth habit, i.e., erect instead of pendulous pods borne at the base rather than the top of the plant.
They also vary in terms of seed coloring, texture, size, and weather resistance.
Let’s look at 5 popular mung bean varieties in closer detail:
- ‘Regur’ or ‘Black Gram’ – Matte, dark-gray seeds; erect, low-growing pods; tolerant to waterlogging; hairy pod; height: 1-2 feet.
- ‘Golden Gram’ – Shiny, yellow seeds; grown for forage; mature pods tend to shatter; height: 0.7-0.9 feet.
- ‘Crystal’– Large, shiny green seeds; erect pods; high resistance to powdery mildew and halo blight; suited to spring/summer planting; height: 2-3 feet.
- ‘Berken’ – Medium-large, shiny green seed; preferred for sprouting; prone to powdery mildew and weather damage; height: 1 foot.
- ‘Satin II’– Dull, green seeds; even seed size and coloring; good resistance to tan spot and powdery mildew; height: 2-4 feet.
Best Places To Buy Mung Bean Seeds
Mung Bean Seed Planting & Germination
- Garden rake
- Mason jar
1. Prepare Planting Site 2-3 Weeks After Last Frost Date
At least 2 weeks after the last expected frost date in your area, prepare a full sun planting site.
Loosen the top 5-6 inches of native soil and remove any weeds or clods. Next, add 4 inches or so of compost – tilling it into the soil bed.
Seeds should be sown 2 inches apart in rows spaced 30-36 inches apart from each other.
2. Soak Beans Before Sowing Them 1-3 inches Deep in Soil
Soak the mung bean seeds in a jar of tepid water for 2-4 hours. While waiting, water the prepared soil bed so it is evenly moist.
Next, plant each seed an inch deep into the soil or 3 inches deep into loose soil or in dry-land gardens/ drought-affected areas.
Maintain a moist soil bed and keep the area weed free.
3. Beans Will Form Once Plant reaches 15-18 inches Tall
Around 50-60 days after planting, a cluster of pale yellow flowers should appear and continue flowering for a month. Beans begin to form once the plant measures 15-18 inches tall.
By day 100 there should be around 30-40 bean pods per mung bean plant, each maturing from dark brown to black and measuring 5 inches long.
By early-mid September, the dried pods will be ready for harvesting.
Growing Mung Bean Sprouts
- Place 2 tablespoons of seeds in a sterile sprouting jar, and fill the jar with just enough room temperature water to cover the seeds.
- Cover with the the mesh lid, and let the seeds soak overnight for 8-12 hours. Keep them in a cool, dark area like a kitchen cupboard (light will result in bitter-tasting sprouts!).
- After soaking, drain the seeds through the mesh lid, and rinse thoroughly in room temperature water.
- Continue a cycle of rinsing and draining the jar 2-3 times per day for the next 2-3 days – returning the jar to a cool, dark area overnight with the jar set on its side.
- After 4 days, the beans should sprout white tails measuring ½ inch. Continue rinsing and draining until the sprouts measure 1½ inches.
- Drain and allow them to dry on a paper towel before storing them in an airtight container in the refrigerator for 4-5 days.
- Soak the seeds overnight in a sprouting jar as before for 8-12 hours.
- Line a tray or flat bowl with a clean water-dampened flannel.
- Rinse the seeds in tepid water and spread them evenly on the flannel.
- Cover tray/bowl with cling wrap, and cover again with newspaper to block out light. Place in a cool, dark area.
- After 6-9 days, the bean shoots should measure 1-1½ inches. Rinse them thoroughly, and cook in salted water for 2 minutes or store in the refrigerator for later.
3 Tips for Growing Mung Bean From Seed
- Mung beans will grow well in an ideal environment, but coating them first in legume inoculant powder (a beneficial microbial amendment) can encourage growth in the soil where beans have never been planted before – after soaking your seeds, place 1-2 tablespoon of inoculant in a sealed storage bag, drain the seeds, and add them to the bag. Shake the bag enough to coat the seeds entirely.
- Check seedlings regularly for signs of pest damage and disease – water evenly to prevent stunted growth or yellowing/browning leaves and spray the foliage with neem oil (a natural pesticide) to deter sap-sucking bugs.
- Keep a record of your growing methods for future planting or sprouting reference. Make not of things such as germination rate, soil used, soaking times etc.
Growing & Caring for Mung Bean
Now you know how simple it is to sow mung bean seeds outdoors, you’re no doubt keen to get started, but don’t go just yet!
If you want to grow healthy and abundant bean pods, make sure your plant has everything it needs to thrive.
Mung beans perform best in fertile, sandy loam soil that drains well as waterlogged mediums will soon invite root rot and other issues.
A soil pH between 6.2-7.2 (neutral-slightly alkaline) is also ideal so perform a soil test (this device produces an instant reading), and amend as necessary with lime, potassium, calcium, or elemental sulfur.
These are warm-season plants native to India, so at least 8-10 hours of full sunlight is needed daily for best results.
Watering & Fertilizing
If the prepared soil bed is adequately moist, mung bean plants should survive without water for the first 2-3 weeks after planting.
After this time, check the first few inches of soil regularly and only water when dry. Depending on typical rainfall and humidity, only one deep watering a month or every two weeks may be necessary.
After planting, a low-nitrogen fertilizer (I recommend this one) may be applied once to encourage earlier growth.
Once two-thirds of the mung bean plants in the patch measure 18 inches tall and have developed dried 5-inch pods, don some gardening gloves and pull up the plants from the soil or use pruning shears to cut at soil level.
Tie the plants in bundles and hang them to dry in a well-ventilated garage/shed before threshing the 12-15 mung beans from the black seed pods and leaving them on a paper towel to dry.
Store the dry beans in a sealed airtight jar where they’ll keep for many years!
Mung Bean Common Questions:
Are Mung Beans Seeds?
Yes. Mung beans are technically classed as sprouting legumes, but all legumes are the edible seeds contained within the seed pod of a plant.
Mung beans are related to the legume family (Fabaceae); legumes are defined by Merriam-Webster as “the fruit or seed of plants.”
How Fast Do Mung Bean Seeds Grow?
From the time of planting directly into garden soil to the moment they reach 1½ feet tall, mung bean seeds take around 3 to 4 months between May/June to September to fully grow.
How Long Does It Take Mung Beans To Sprout?
Mung beans normally reach a mature, edible form in 3-9 days depending on the specific sprouting method.
Mung beans germinated in a sprouting jar will develop shoots within 3-4 days while those grown on a tray in dark, humid conditions can expect to sprout in 6-9 days.
Is It Necessary To Soak Mung Beans?
Soaking mung beans is recommended prior to planting to help them swell in order to germinate more easily in the soil.
Soaking is also strongly advised during the sprouting process since this softens the outer bean coating, which would otherwise bypass the small intestine without being fully digested.