Plant care
Greater Celandinetemperature & humidity
Chelidonium majus
More about greater celandine
Ideal temperature for greater celandine
Temperature kills fewer greater celandine 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 -15–30°C (5–86°F) is fine; the spot you put the plant in matters more. Below roughly -15°C growth pauses; cold beyond that pushes it into dormancy rather than killing it outright.
Cold tolerance & winter care
Greater Celandine is comparatively hardy (USDA 5–9, 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 greater celandine
Greater Celandine sits happiest at around 40–70% relative humidity. Tolerant of the average ambient humidity of temperate European and North American climates. Not sensitive to humidity extremes; performs well in typical UK and US garden conditions. Good air circulation reduces the risk of fungal issues in damp microclimates. 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.
Greater Celandine temperature & humidity — frequently asked questions
What temperature is best for greater celandine?
Greater Celandine grows best between -15–30°C (5–86°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 greater celandine tolerate?
Greater Celandine starts to suffer below roughly -15°C. It tolerates a cold dormant period within USDA 5–9, but a wet cold root zone is more dangerous than cold air.
What humidity does greater celandine need?
Greater Celandine prefers about 40–70% relative humidity. Tolerant of the average ambient humidity of temperate European and North American climates. Not sensitive to humidity extremes; performs well in typical UK and US garden conditions. Good air circulation reduces the risk of fungal issues in damp microclimates.
How do I raise humidity for greater celandine?
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 greater celandine live outside?
Greater Celandine is rated for USDA zone 5–9 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 greater celandine care
In the UK? Keeping greater celandine warm in a UK home covers the radiator, single-glazing and heating-season humidity angle. Temperature and humidity are one piece. See the full greater celandine care guide, its cold-hardiness guide, and watering schedule — humidity and watering problems are easy to confuse.