Plant care
Crystal Palace Lobeliatemperature & humidity
Lobelia erinus
More about crystal palace lobelia
Ideal temperature for crystal palace lobelia
Crystal Palace Lobelia is comfortable in any room a person is comfortable in, roughly 10-23°C (50-73°F). The mistakes are micro-climates: a north-facing window on a frosty night, a south-facing windowsill in a summer heatwave, the standing draught between an opened kitchen door and the radiator behind it. Read the room around the plant, not the thermostat. Below roughly 10°C the damage starts — soft blackened patches, translucent leaves, sometimes overnight.
Cold tolerance & winter care
Crystal Palace Lobelia is frost-tender (USDA 2-11 (frost-tender annual in most temperate zones), 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 crystal palace lobelia
Crystal Palace Lobelia sits happiest at around 50-70% relative humidity. As a South African coastal native, Lobelia erinus appreciates moderate to higher humidity. In very dry, hot conditions growth slows and the plant may enter dormancy; a light shear and extra watering often prompts a fresh flush in late summer. 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.
Crystal Palace Lobelia temperature & humidity — frequently asked questions
What temperature is best for crystal palace lobelia?
Crystal Palace Lobelia grows best between 10-23°C (50-73°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 crystal palace lobelia tolerate?
Crystal Palace Lobelia 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 crystal palace lobelia need?
Crystal Palace Lobelia prefers about 50-70% relative humidity. As a South African coastal native, Lobelia erinus appreciates moderate to higher humidity. In very dry, hot conditions growth slows and the plant may enter dormancy; a light shear and extra watering often prompts a fresh flush in late summer.
How do I raise humidity for crystal palace lobelia?
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 crystal palace lobelia live outside?
Crystal Palace Lobelia is rated for USDA zone 2-11 (frost-tender annual in most temperate zones) 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 crystal palace lobelia care
In the UK? Keeping crystal palace lobelia warm in a UK home covers the radiator, single-glazing and heating-season humidity angle. Temperature and humidity are one piece. See the full crystal palace lobelia care guide, its cold-hardiness guide, and watering schedule — humidity and watering problems are easy to confuse.