Plant care
Membrane-flowered Stelistemperature & humidity
Stelis hymenantha
More about membrane-flowered stelis
Ideal temperature for membrane-flowered stelis
Temperature kills fewer membrane-flowered stelis 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 9–21°C (48–70°F) is fine; the spot you put the plant in matters more. Below roughly 9°C the damage starts — soft blackened patches, translucent leaves, sometimes overnight.
Cold tolerance & winter care
Membrane-flowered Stelis is frost-tender (USDA 11-12, 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 membrane-flowered stelis
Membrane-flowered Stelis sits happiest at around 75–90% relative humidity. Consistently high humidity is critical. Use a closed orchid case or dedicated cool greenhouse section. Run a small fan continuously to prevent fungal spotting. Avoid misting the flowers directly once open, as wet blooms deteriorate rapidly. 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.
Membrane-flowered Stelis temperature & humidity — frequently asked questions
What temperature is best for membrane-flowered stelis?
Membrane-flowered Stelis grows best between 9–21°C (48–70°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 membrane-flowered stelis tolerate?
Membrane-flowered Stelis starts to suffer below roughly 9°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 membrane-flowered stelis need?
Membrane-flowered Stelis prefers about 75–90% relative humidity. Consistently high humidity is critical. Use a closed orchid case or dedicated cool greenhouse section. Run a small fan continuously to prevent fungal spotting. Avoid misting the flowers directly once open, as wet blooms deteriorate rapidly.
How do I raise humidity for membrane-flowered stelis?
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 membrane-flowered stelis live outside?
Membrane-flowered Stelis is rated for USDA zone 11-12 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 membrane-flowered stelis care
In the UK? Keeping membrane-flowered stelis warm in a UK home covers the radiator, single-glazing and heating-season humidity angle. Temperature and humidity are one piece. See the full membrane-flowered stelis care guide, its cold-hardiness guide, and watering schedule — humidity and watering problems are easy to confuse.