Plant care
Green Rotalatemperature & humidity
Rotala sp. 'Green'
More about green rotala
Ideal temperature for green rotala
Aim for 20-28°C (68-82°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 20°C the damage starts — soft blackened patches, translucent leaves, sometimes overnight.
Cold tolerance & winter care
Green Rotala is frost-tender (USDA 10-12 (aquatic/indoor only in temperate climates), RHS H1b). 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 green rotala
Green Rotala sits happiest at around N/A (aquatic) or 60-80% emersed relative humidity. Fully submerged in aquarium culture. Emersed forms tolerate moderate humidity but may produce different leaf shapes than the submersed form. 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.
Green Rotala temperature & humidity — frequently asked questions
What temperature is best for green rotala?
Green Rotala grows best between 20-28°C (68-82°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 green rotala tolerate?
Green Rotala starts to suffer below roughly 20°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 green rotala need?
Green Rotala prefers about N/A (aquatic) or 60-80% emersed relative humidity. Fully submerged in aquarium culture. Emersed forms tolerate moderate humidity but may produce different leaf shapes than the submersed form.
How do I raise humidity for green rotala?
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 green rotala live outside?
Green Rotala is rated for USDA zone 10-12 (aquatic/indoor only in temperate climates) and RHS hardiness H1b. Outside that range it must come indoors before the first frost — treat any outdoor stint as a summer holiday, not a permanent home.
More green rotala care
In the UK? Keeping green rotala warm in a UK home covers the radiator, single-glazing and heating-season humidity angle. Temperature and humidity are one piece. See the full green rotala care guide, its cold-hardiness guide, and watering schedule — humidity and watering problems are easy to confuse.