Plant care
Slender-Leaved Sundewtemperature & humidity
Drosera linearis
More about slender-leaved sundew
Ideal temperature for slender-leaved sundew
Temperature kills fewer slender-leaved sundew 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 5–28°C (41–82°F) is fine; the spot you put the plant in matters more. Below roughly 5°C growth pauses; cold beyond that pushes it into dormancy rather than killing it outright.
Cold tolerance & winter care
Slender-Leaved Sundew is comparatively hardy (USDA 3-6, RHS H6). 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 slender-leaved sundew
Slender-Leaved Sundew sits happiest at around 50–80% relative humidity. Moderate to high humidity suits this species; it grows in open fens with good air movement, so stagnant high humidity can promote fungal issues. Good ventilation is important, especially during cool dormancy. 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.
Slender-Leaved Sundew temperature & humidity — frequently asked questions
What temperature is best for slender-leaved sundew?
Slender-Leaved Sundew grows best between 5–28°C (41–82°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 slender-leaved sundew tolerate?
Slender-Leaved Sundew starts to suffer below roughly 5°C. It tolerates a cold dormant period within USDA 3-6, but a wet cold root zone is more dangerous than cold air.
What humidity does slender-leaved sundew need?
Slender-Leaved Sundew prefers about 50–80% relative humidity. Moderate to high humidity suits this species; it grows in open fens with good air movement, so stagnant high humidity can promote fungal issues. Good ventilation is important, especially during cool dormancy.
How do I raise humidity for slender-leaved sundew?
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 slender-leaved sundew live outside?
Slender-Leaved Sundew is rated for USDA zone 3-6 and RHS hardiness H6. 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 slender-leaved sundew care
In the UK? Keeping slender-leaved sundew warm in a UK home covers the radiator, single-glazing and heating-season humidity angle. Temperature and humidity are one piece. See the full slender-leaved sundew care guide, its cold-hardiness guide, and watering schedule — humidity and watering problems are easy to confuse.