Growli

Plant care

Giant Feather Grasstemperature & humidity

Stipa gigantea

RHS H5USDA 7-10Mildly toxic to pets

More about giant feather grass

Ideal temperature for giant feather grass

Temperature kills fewer giant feather grass 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 to 30°C (5 to 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

Giant Feather Grass is comparatively hardy (USDA 7-10 (outdoor hardy), RHS H5). 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 giant feather grass

Giant Feather Grass sits happiest at around Ambient outdoor humidity relative humidity. A hardy garden grass indifferent to humidity. Good air movement keeps the foliage dry and rot-free; it dislikes stagnant, sheltered, damp corners. 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.

Giant Feather Grass temperature & humidity — frequently asked questions

What temperature is best for giant feather grass?

Giant Feather Grass grows best between -15 to 30°C (5 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 giant feather grass tolerate?

Giant Feather Grass starts to suffer below roughly -15°C. It tolerates a cold dormant period within USDA 7-10 (outdoor hardy), but a wet cold root zone is more dangerous than cold air.

What humidity does giant feather grass need?

Giant Feather Grass prefers about Ambient outdoor humidity relative humidity. A hardy garden grass indifferent to humidity. Good air movement keeps the foliage dry and rot-free; it dislikes stagnant, sheltered, damp corners.

How do I raise humidity for giant feather grass?

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 giant feather grass live outside?

Giant Feather Grass is rated for USDA zone 7-10 (outdoor hardy) and RHS hardiness H5. 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 giant feather grass care

In the UK? Keeping giant feather grass warm in a UK home covers the radiator, single-glazing and heating-season humidity angle. Temperature and humidity are one piece. See the full giant feather grass care guide, its cold-hardiness guide, and watering schedule — humidity and watering problems are easy to confuse.