Plant care
Snow-in-Summertemperature & humidity
Cerastium tomentosum
More about snow-in-summer
Ideal temperature for snow-in-summer
Temperature kills fewer snow-in-summer 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 -30 to 30°C (-22 to 86°F) is fine; the spot you put the plant in matters more. Below roughly -30°C growth pauses; cold beyond that pushes it into dormancy rather than killing it outright.
Cold tolerance & winter care
Snow-in-Summer is comparatively hardy (USDA 3–7, RHS H7). Within that range it tolerates a cold dormant spell outdoors; outside it, grow it in a container you can move under cover or overwinter in a cool but frost-free spot. Hardiness assumes an established plant in well-drained soil — a wet, cold root zone kills far more plants than cold air alone.
Humidity for snow-in-summer
Snow-in-Summer sits happiest at around Low (20–50% RH) relative humidity. The dense, woolly trichomes on the foliage are a drought and heat adaptation. High humidity promotes fungal diseases in the foliage. Good air circulation is important in wetter climates. 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.
Snow-in-Summer temperature & humidity — frequently asked questions
What temperature is best for snow-in-summer?
Snow-in-Summer grows best between -30 to 30°C (-22 to 86°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 snow-in-summer tolerate?
Snow-in-Summer starts to suffer below roughly -30°C. It tolerates a cold dormant period within USDA 3–7, but a wet cold root zone is more dangerous than cold air.
What humidity does snow-in-summer need?
Snow-in-Summer prefers about Low (20–50% RH) relative humidity. The dense, woolly trichomes on the foliage are a drought and heat adaptation. High humidity promotes fungal diseases in the foliage. Good air circulation is important in wetter climates.
How do I raise humidity for snow-in-summer?
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 snow-in-summer live outside?
Snow-in-Summer is rated for USDA zone 3–7 and RHS hardiness H7. Within that range it can stay outdoors; outside it, grow it in a moveable container and protect the roots from a wet, cold winter.
More snow-in-summer care
In the UK? Keeping snow-in-summer warm in a UK home covers the radiator, single-glazing and heating-season humidity angle. Temperature and humidity are one piece. See the full snow-in-summer care guide, its cold-hardiness guide, and watering schedule — humidity and watering problems are easy to confuse.