Plant care
Mung Beantemperature & humidity
Vigna radiata
More about mung bean
Ideal temperature for mung bean
Temperature kills fewer mung bean plants than you'd think. What kills them is the micro-climate within a normal-temperature room — a leaf pressed against single-glazed winter glass, the hot dry updraft directly above a radiator, the cold blast from an AC vent. The thermostat reading at 20–35°C (68–95°F) is fine; the spot you put the plant in matters more. Below roughly 20°C the damage starts — soft blackened patches, translucent leaves, sometimes overnight.
Cold tolerance & winter care
Mung Bean is frost-tender (USDA 9-11 (grown as annual in zones 4-8), RHS H1b). It cannot survive a frost, so in most of the US and UK it lives indoors year-round or summers outside and comes back in well before the first autumn frost — once nights drop toward 10-12°C is the cue, not the first frost warning. Acclimate it over a week when moving between indoors and out so the leaves do not shock.
Humidity for mung bean
Mung Bean sits happiest at around 40–70% relative humidity. Prefers moderate humidity. Excessively humid conditions during ripening cause pods to split and seeds to mold. Ensure good air movement. Dry weather at harvest is ideal for even pod maturation. The usual low-humidity tell is crisp brown leaf tips and edges while the soil moisture is fine — a sign the air, not the watering, is the problem. If you need to raise it, the reliable methods are grouping plants together, standing the pot on a tray of damp pebbles (the pot above the waterline, never in it), or running a small humidifier in winter when indoor heating dries the air most. Misting is the least effective — it raises humidity for minutes, not hours.
Mung Bean temperature & humidity — frequently asked questions
What temperature is best for mung bean?
Mung Bean grows best between 20–35°C (68–95°F). Keep it out of cold draughts, off freezing windowsills in winter, and away from the hot dry air directly above radiators — the extremes matter far more than the average room temperature.
How cold can mung bean tolerate?
Mung Bean starts to suffer below roughly 20°C. It is frost-tender and will be damaged or killed by a frost, so bring it indoors once nights fall toward 10-12°C.
What humidity does mung bean need?
Mung Bean prefers about 40–70% relative humidity. Prefers moderate humidity. Excessively humid conditions during ripening cause pods to split and seeds to mold. Ensure good air movement. Dry weather at harvest is ideal for even pod maturation.
How do I raise humidity for mung bean?
Group it with other plants, stand the pot on a tray of damp pebbles (kept above the waterline), or run a small humidifier in winter. Misting only helps for a few minutes, so it is the weakest option for a plant that genuinely needs more humidity.
Can mung bean live outside?
Mung Bean is rated for USDA zone 9-11 (grown as annual in zones 4-8) and RHS hardiness H1b. Outside that range it must come indoors before the first frost — treat any outdoor stint as a summer holiday, not a permanent home.
More mung bean care
In the UK? Keeping mung bean warm in a UK home covers the radiator, single-glazing and heating-season humidity angle. Temperature and humidity are one piece. See the full mung bean care guide, its cold-hardiness guide, and watering schedule — humidity and watering problems are easy to confuse.