Plant care
Utricularia subulatatemperature & humidity
Utricularia subulata
More about utricularia subulata
Ideal temperature for utricularia subulata
Aim for 15-30°C; protect from hard frost (59-86°F; protect from hard frost) 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 15°C the damage starts — soft blackened patches, translucent leaves, sometimes overnight.
Cold tolerance & winter care
Utricularia subulata is frost-tender (USDA 8-11 (warm-temperate to tropical; protect from sustained frost), RHS H2). 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 utricularia subulata
Utricularia subulata sits happiest at around 50-80% relative humidity. Appreciates humid air but the key requirement is a saturated root zone rather than high ambient humidity. Grows happily in open bog gardens and terrariums alike. 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.
Utricularia subulata temperature & humidity — frequently asked questions
What temperature is best for utricularia subulata?
Utricularia subulata grows best between 15-30°C; protect from hard frost (59-86°F; protect from hard frost). 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 utricularia subulata tolerate?
Utricularia subulata starts to suffer below roughly 15°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 utricularia subulata need?
Utricularia subulata prefers about 50-80% relative humidity. Appreciates humid air but the key requirement is a saturated root zone rather than high ambient humidity. Grows happily in open bog gardens and terrariums alike.
How do I raise humidity for utricularia subulata?
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 utricularia subulata live outside?
Utricularia subulata is rated for USDA zone 8-11 (warm-temperate to tropical; protect from sustained frost) and RHS hardiness H2. Outside that range it must come indoors before the first frost — treat any outdoor stint as a summer holiday, not a permanent home.
More utricularia subulata care
In the UK? Keeping utricularia subulata warm in a UK home covers the radiator, single-glazing and heating-season humidity angle. Temperature and humidity are one piece. See the full utricularia subulata care guide, its cold-hardiness guide, and watering schedule — humidity and watering problems are easy to confuse.