Plant care
Oleandertemperature & humidity
Nerium oleander
More about oleander
Ideal temperature for oleander
Temperature kills fewer oleander 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 10-30°C (50-86°F) is fine; the spot you put the plant in matters more. Below roughly 10°C growth pauses; cold beyond that pushes it into dormancy rather than killing it outright.
Cold tolerance & winter care
Oleander is comparatively hardy (USDA 8-11 (overwinter under glass in colder zones), RHS H4). 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 oleander
Oleander sits happiest at around 30-50% relative humidity. A Mediterranean shrub that prefers warm, dry air and resents stagnant humid conditions, which encourage scale and sooty mould. No misting needed. 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.
Oleander temperature & humidity — frequently asked questions
What temperature is best for oleander?
Oleander grows best between 10-30°C (50-86°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 oleander tolerate?
Oleander starts to suffer below roughly 10°C. It tolerates a cold dormant period within USDA 8-11 (overwinter under glass in colder zones), but a wet cold root zone is more dangerous than cold air.
What humidity does oleander need?
Oleander prefers about 30-50% relative humidity. A Mediterranean shrub that prefers warm, dry air and resents stagnant humid conditions, which encourage scale and sooty mould. No misting needed.
How do I raise humidity for oleander?
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 oleander live outside?
Oleander is rated for USDA zone 8-11 (overwinter under glass in colder zones) and RHS hardiness H4. 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 oleander care
In the UK? Keeping oleander warm in a UK home covers the radiator, single-glazing and heating-season humidity angle. Temperature and humidity are one piece. See the full oleander care guide, its cold-hardiness guide, and watering schedule — humidity and watering problems are easy to confuse.