🫘 Oklahoma 12 Mung Bean

What it looks like

No verified photo of ‘Oklahoma 12’ itself was found, so the pictures below show the species — the same plant, photographed generally.

Why this variety

Oklahoma 12 is mungbean history you can plant. In 1963, the Oklahoma Agricultural Experiment Station released three mungbean cultivars developed by selection from introduced germplasm — Berken, Oklahoma 12, and Kiloga — and Oklahoma 12 is the small-seeded one of the trio. Small seed matters for sprouting: sprout guides list Oklahoma 12 among the smallest-seeded mungbean varieties, which means the cotyledons and seed coats stay proportionate and the sprouts come out clean.

In the field, genebank records give Oklahoma 12 about 42 days to flower and 79 days to maturity — a compact, early-maturing plant in the classic mungbean mold. For Florida, that earliness is gold: mungbean is a short-duration, heat-loving crop, and a variety that finishes in under 80 days can dodge the worst of the wet season if you time it right.

If you have not grown the species before, start with the Mung Bean growing guide for the general picture, then come back here for what makes this variety different.

How to grow

Direct-sow Oklahoma 12 after soil is genuinely warm — at least 65-70°F, since germination fails below 65°F — about an inch deep, 4 inches apart in rows 18-24 inches apart, in full sun. Soaking seed 4-6 hours speeds sprouting, which takes 3-10 days. Plants are upright and bushy, 1-2 feet tall, and most mungbeans are short-day sensitive, so flowering follows shortening days.

Oklahoma 12 tolerates drought once established but sets seed poorly if rain falls during flowering — which, in Florida, means watching the forecast at bloom time and accepting that a rainy bloom week costs yield. Work a little compost or castings in at planting; no fertilizer is needed in fertile soil, since mungbeans fix their own nitrogen.

Water & feeding

Keep soil evenly moist but never waterlogged, about an inch a week, and mulch to hold moisture. Reduce watering as pods dry — dry pods are the goal, and late water invites mold on maturing pods. Base watering beats overhead watering in humid weather.

Common problems

• Cold soil — the most common failure; wait for genuinely warm soil.
• Pods shattering — pods mature unevenly, so pick 2-5 times as pods darken rather than waiting for one big harvest.
• Aphids, thrips, and pod borers — row cover early and scout regularly.
• Powdery mildew and leaf spot in humid weather — space for airflow and avoid overhead watering.

Harvest

For sprouts, sprout seed indoors in 3-5 days in the dark with twice-daily rinsing, using food-safe seed and careful hygiene — Oklahoma 12’s small seeds are made for this. For dry beans, pick pods as they darken, shell, and dry fully before storing airtight in a cool, dark place. Mung beans cook faster than most dry beans and need no overnight soak in many recipes — dal in under an hour from your own garden.

Saving seeds

Oklahoma 12 is mungbean history you can plant. In 1963, the Oklahoma Agricultural Experiment Station released three mungbean cultivars developed by selection from introduced germplasm — Berken, Oklahoma 12, and Kiloga — and Oklahoma 12 is the small-seeded one of the trio. Small seed matters for sprouting: sprout guides list Oklahoma 12 among the smallest-seeded mungbean varieties, which means the cotyledons and seed coats stay proportionate and the sprouts come out clean. As an open-pollinated selection it comes true from seed: direct-sow after soil is genuinely warm — at least 65 to 70°F, since germination fails below 65°F — about an inch deep, 4 inches apart in rows 18 to 24 inches apart, in full sun. The full method is in the Saving seeds section of the Mung Bean guide.