Plant care
Bent Alligator Flagtemperature & humidity
Thalia geniculata
More about bent alligator flag
Ideal temperature for bent alligator flag
Aim for 10°C to 38°C (50°F to 100°F) on the thermostat and you've handled the easy part. The hard part is the half-metre around the plant: window glass that drops to near-freezing on a January night, a radiator pumping out hot dry air, a draught from an opened front door. Move the plant 30 cm and you've usually fixed the problem. Below roughly 10°C the damage starts — soft blackened patches, translucent leaves, sometimes overnight.
Cold tolerance & winter care
Bent Alligator Flag is frost-tender (USDA 9–11, RHS H1c). It cannot survive a frost, so in most of the US and UK it lives indoors year-round or summers outside and comes back in well before the first autumn frost — once nights drop toward 10-12°C is the cue, not the first frost warning. Acclimate it over a week when moving between indoors and out so the leaves do not shock.
Humidity for bent alligator flag
Bent Alligator Flag sits happiest at around 70–100% relative humidity. Native to tropical and subtropical wetlands where humidity is consistently high. Outdoors in its hardy range it requires no additional humidity management. In cooler climates where plants are brought indoors for winter, maintain high humidity by grouping with other plants or standing on a pebble tray with water. 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.
Bent Alligator Flag temperature & humidity — frequently asked questions
What temperature is best for bent alligator flag?
Bent Alligator Flag grows best between 10°C to 38°C (50°F to 100°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 bent alligator flag tolerate?
Bent Alligator Flag starts to suffer below roughly 10°C. It is frost-tender and will be damaged or killed by a frost, so bring it indoors once nights fall toward 10-12°C.
What humidity does bent alligator flag need?
Bent Alligator Flag prefers about 70–100% relative humidity. Native to tropical and subtropical wetlands where humidity is consistently high. Outdoors in its hardy range it requires no additional humidity management. In cooler climates where plants are brought indoors for winter, maintain high humidity by grouping with other plants or standing on a pebble tray with water.
How do I raise humidity for bent alligator flag?
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 bent alligator flag live outside?
Bent Alligator Flag is rated for USDA zone 9–11 and RHS hardiness H1c. Outside that range it must come indoors before the first frost — treat any outdoor stint as a summer holiday, not a permanent home.
More bent alligator flag care
In the UK? Keeping bent alligator flag warm in a UK home covers the radiator, single-glazing and heating-season humidity angle. Temperature and humidity are one piece. See the full bent alligator flag care guide, its cold-hardiness guide, and watering schedule — humidity and watering problems are easy to confuse.