Plant care
Graptopetalum macdougalliitemperature & humidity
Graptopetalum macdougallii
More about graptopetalum macdougallii
Ideal temperature for graptopetalum macdougallii
Aim for 18-27°C (65-80°F) on the thermostat and you've handled the easy part. The hard part is the half-metre around the plant: window glass that drops to near-freezing on a January night, a radiator pumping out hot dry air, a draught from an opened front door. Move the plant 30 cm and you've usually fixed the problem. Below roughly 18°C the damage starts — soft blackened patches, translucent leaves, sometimes overnight.
Cold tolerance & winter care
Graptopetalum macdougallii is frost-tender (USDA 9-11 (frost-tender; some sources note brief tolerance to light frost, but protect below ~2°C), RHS H2). 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 graptopetalum macdougallii
Graptopetalum macdougallii sits happiest at around 30-50% relative humidity. Tolerant of dry air and happiest in low to average humidity. Good airflow keeps the clustered rosettes free of fungal problems and protects the farina coating. 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.
Graptopetalum macdougallii temperature & humidity — frequently asked questions
What temperature is best for graptopetalum macdougallii?
Graptopetalum macdougallii grows best between 18-27°C (65-80°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 graptopetalum macdougallii tolerate?
Graptopetalum macdougallii starts to suffer below roughly 18°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 graptopetalum macdougallii need?
Graptopetalum macdougallii prefers about 30-50% relative humidity. Tolerant of dry air and happiest in low to average humidity. Good airflow keeps the clustered rosettes free of fungal problems and protects the farina coating.
How do I raise humidity for graptopetalum macdougallii?
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 graptopetalum macdougallii live outside?
Graptopetalum macdougallii is rated for USDA zone 9-11 (frost-tender; some sources note brief tolerance to light frost, but protect below ~2°C) and RHS hardiness H2. Outside that range it must come indoors before the first frost — treat any outdoor stint as a summer holiday, not a permanent home.
More graptopetalum macdougallii care
In the UK? Keeping graptopetalum macdougallii warm in a UK home covers the radiator, single-glazing and heating-season humidity angle. Temperature and humidity are one piece. See the full graptopetalum macdougallii care guide, its cold-hardiness guide, and watering schedule — humidity and watering problems are easy to confuse.