Plant care
Hair sedgetemperature & humidity
Carex comans 'Frosted Curls'
More about hair sedge
Ideal temperature for hair sedge
Temperature kills fewer hair sedge 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°C to 30°C (14°F to 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
Hair sedge is comparatively hardy (USDA 6-10, 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 hair sedge
Hair sedge sits happiest at around Low to moderate (30–60% RH) relative humidity. Tolerates a wide range of ambient humidity. Native to New Zealand's open grasslands, it is adapted to outdoor conditions and does not require elevated humidity. Good air circulation helps prevent fungal issues around the crown. 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.
Hair sedge temperature & humidity — frequently asked questions
What temperature is best for hair sedge?
Hair sedge grows best between -10°C to 30°C (14°F 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 hair sedge tolerate?
Hair sedge starts to suffer below roughly -10°C. It tolerates a cold dormant period within USDA 6-10, but a wet cold root zone is more dangerous than cold air.
What humidity does hair sedge need?
Hair sedge prefers about Low to moderate (30–60% RH) relative humidity. Tolerates a wide range of ambient humidity. Native to New Zealand's open grasslands, it is adapted to outdoor conditions and does not require elevated humidity. Good air circulation helps prevent fungal issues around the crown.
How do I raise humidity for hair sedge?
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 hair sedge live outside?
Hair sedge is rated for USDA zone 6-10 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 hair sedge care
In the UK? Keeping hair sedge warm in a UK home covers the radiator, single-glazing and heating-season humidity angle. Temperature and humidity are one piece. See the full hair sedge care guide, its cold-hardiness guide, and watering schedule — humidity and watering problems are easy to confuse.