Plant care
Rowantemperature & humidity
Sorbus aucuparia
More about rowan
Ideal temperature for rowan
Rowan is comfortable in any room a person is comfortable in, roughly Hardy to about -30°C; thrives in cool temperate summers (Hardy to about -22°F; thrives in cool temperate summers). The mistakes are micro-climates: a north-facing window on a frosty night, a south-facing windowsill in a summer heatwave, the standing draught between an opened kitchen door and the radiator behind it. Read the room around the plant, not the thermostat. Below roughly -30°C growth pauses; cold beyond that pushes it into dormancy rather than killing it outright.
Cold tolerance & winter care
Rowan is comparatively hardy (USDA 3-6 (outdoor; dislikes hot summers), 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 rowan
Rowan sits happiest at around Outdoor ambient relative humidity. A fully outdoor tree with no humidity requirement; thrives in the cool, often damp temperate and upland climates of Britain and northern Europe. 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.
Rowan temperature & humidity — frequently asked questions
What temperature is best for rowan?
Rowan grows best between Hardy to about -30°C; thrives in cool temperate summers (Hardy to about -22°F; thrives in cool temperate summers). 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 rowan tolerate?
Rowan starts to suffer below roughly -30°C. It tolerates a cold dormant period within USDA 3-6 (outdoor; dislikes hot summers), but a wet cold root zone is more dangerous than cold air.
What humidity does rowan need?
Rowan prefers about Outdoor ambient relative humidity. A fully outdoor tree with no humidity requirement; thrives in the cool, often damp temperate and upland climates of Britain and northern Europe.
How do I raise humidity for rowan?
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 rowan live outside?
Rowan is rated for USDA zone 3-6 (outdoor; dislikes hot summers) 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 rowan care
In the UK? Keeping rowan warm in a UK home covers the radiator, single-glazing and heating-season humidity angle. Temperature and humidity are one piece. See the full rowan care guide, its cold-hardiness guide, and watering schedule — humidity and watering problems are easy to confuse.