Plant care
Vietnamese Coriandertemperature & humidity
Persicaria odorata
More about vietnamese coriander
Ideal temperature for vietnamese coriander
Vietnamese Coriander is comfortable in any room a person is comfortable in, roughly 14-30°C (optimal); damaged below ~5°C and killed by frost (57-86°F (optimal); damaged below ~40°F and killed by frost). The mistakes are micro-climates: a north-facing window on a frosty night, a south-facing windowsill in a summer heatwave, the standing draught between an opened kitchen door and the radiator behind it. Read the room around the plant, not the thermostat. Below roughly 14°C the damage starts — soft blackened patches, translucent leaves, sometimes overnight.
Cold tolerance & winter care
Vietnamese Coriander is frost-tender (USDA USDA zones 9-11 (frost-free); RHS hardiness H2, tolerating 1-5°C. Overwinter indoors or under glass elsewhere., RHS undefined). 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 vietnamese coriander
Vietnamese Coriander sits happiest at around Moderate to high (50%+) relative humidity. A tropical, humidity-loving herb that thrives in warm, humid conditions. It tolerates average household humidity but grows lushest with higher moisture in the air; very dry indoor air can dry the leaf margins, so group with other plants or mist in heated rooms. 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.
Vietnamese Coriander temperature & humidity — frequently asked questions
What temperature is best for vietnamese coriander?
Vietnamese Coriander grows best between 14-30°C (optimal); damaged below ~5°C and killed by frost (57-86°F (optimal); damaged below ~40°F and killed by frost). 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 vietnamese coriander tolerate?
Vietnamese Coriander starts to suffer below roughly 14°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 vietnamese coriander need?
Vietnamese Coriander prefers about Moderate to high (50%+) relative humidity. A tropical, humidity-loving herb that thrives in warm, humid conditions. It tolerates average household humidity but grows lushest with higher moisture in the air; very dry indoor air can dry the leaf margins, so group with other plants or mist in heated rooms.
How do I raise humidity for vietnamese coriander?
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 vietnamese coriander live outside?
Vietnamese Coriander is rated for USDA zone USDA zones 9-11 (frost-free); RHS hardiness H2, tolerating 1-5°C. Overwinter indoors or under glass elsewhere.. Outside that range it must come indoors before the first frost — treat any outdoor stint as a summer holiday, not a permanent home.
More vietnamese coriander care
In the UK? Keeping vietnamese coriander warm in a UK home covers the radiator, single-glazing and heating-season humidity angle. Temperature and humidity are one piece. See the full vietnamese coriander care guide, its cold-hardiness guide, and watering schedule — humidity and watering problems are easy to confuse.