Plant care
Muster-John-Henrytemperature & humidity
Tagetes minuta
More about muster-john-henry
Ideal temperature for muster-john-henry
Temperature kills fewer muster-john-henry 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 15–35°C (59–95°F) is fine; the spot you put the plant in matters more. Below roughly 15°C the damage starts — soft blackened patches, translucent leaves, sometimes overnight.
Cold tolerance & winter care
Muster-John-Henry is frost-tender (USDA 8-11, RHS H1c). 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 muster-john-henry
Muster-John-Henry sits happiest at around 30–70% relative humidity. Adaptable across a broad humidity range. Good air circulation around the tall stems helps prevent fungal issues in more humid climates. The strong essential oil content provides some natural pest deterrence. 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.
Muster-John-Henry temperature & humidity — frequently asked questions
What temperature is best for muster-john-henry?
Muster-John-Henry grows best between 15–35°C (59–95°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 muster-john-henry tolerate?
Muster-John-Henry starts to suffer below roughly 15°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 muster-john-henry need?
Muster-John-Henry prefers about 30–70% relative humidity. Adaptable across a broad humidity range. Good air circulation around the tall stems helps prevent fungal issues in more humid climates. The strong essential oil content provides some natural pest deterrence.
How do I raise humidity for muster-john-henry?
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 muster-john-henry live outside?
Muster-John-Henry is rated for USDA zone 8-11 and RHS hardiness H1c. Outside that range it must come indoors before the first frost — treat any outdoor stint as a summer holiday, not a permanent home.
More muster-john-henry care
In the UK? Keeping muster-john-henry warm in a UK home covers the radiator, single-glazing and heating-season humidity angle. Temperature and humidity are one piece. See the full muster-john-henry care guide, its cold-hardiness guide, and watering schedule — humidity and watering problems are easy to confuse.