Growli

Plant care

Ipomoea lobatatemperature & humidity

Ipomoea lobata

RHS H2USDA 9-11Toxic to pets

More about ipomoea lobata

Ideal temperature for ipomoea lobata

Aim for 18 to 30°C (64 to 86°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 18°C the damage starts — soft blackened patches, translucent leaves, sometimes overnight.

Cold tolerance & winter care

Ipomoea lobata is frost-tender (USDA 9-11 (grown as a frost-tender annual elsewhere), 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 ipomoea lobata

Ipomoea lobata sits happiest at around 40-70% relative humidity. A warm-season annual untroubled by humidity levels. Ordinary outdoor summer air is fine; no humidity intervention needed. 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.

Ipomoea lobata temperature & humidity — frequently asked questions

What temperature is best for ipomoea lobata?

Ipomoea lobata grows best between 18 to 30°C (64 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 ipomoea lobata tolerate?

Ipomoea lobata starts to suffer below roughly 18°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 ipomoea lobata need?

Ipomoea lobata prefers about 40-70% relative humidity. A warm-season annual untroubled by humidity levels. Ordinary outdoor summer air is fine; no humidity intervention needed.

How do I raise humidity for ipomoea lobata?

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 ipomoea lobata live outside?

Ipomoea lobata is rated for USDA zone 9-11 (grown as a frost-tender annual elsewhere) 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 ipomoea lobata care

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