Plant care
Crossandra (firecracker flower)temperature & humidity
Crossandra infundibuliformis
More about crossandra (firecracker flower)
Ideal temperature for crossandra (firecracker flower)
Crossandra (firecracker flower) is comfortable in any room a person is comfortable in, roughly 18-27°C (65-80°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 18°C the damage starts — soft blackened patches, translucent leaves, sometimes overnight.
Cold tolerance & winter care
Crossandra (firecracker flower) is frost-tender (USDA 10a-11b outdoors; grown as a houseplant or under glass elsewhere, RHS H1b (tender; indoor or heated greenhouse in the UK, can summer outdoors above ~12°C)). 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 crossandra (firecracker flower)
Crossandra (firecracker flower) sits happiest at around 50-60%+ relative humidity. A high-humidity lover. Group it with other plants, stand the pot on a pebble-and-water tray (base above the waterline), or run a humidifier. Dry indoor air encourages spider mites and crisp leaf edges. 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.
Crossandra (firecracker flower) temperature & humidity — frequently asked questions
What temperature is best for crossandra (firecracker flower)?
Crossandra (firecracker flower) grows best between 18-27°C (65-80°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 crossandra (firecracker flower) tolerate?
Crossandra (firecracker flower) 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 crossandra (firecracker flower) need?
Crossandra (firecracker flower) prefers about 50-60%+ relative humidity. A high-humidity lover. Group it with other plants, stand the pot on a pebble-and-water tray (base above the waterline), or run a humidifier. Dry indoor air encourages spider mites and crisp leaf edges.
How do I raise humidity for crossandra (firecracker flower)?
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 crossandra (firecracker flower) live outside?
Crossandra (firecracker flower) is rated for USDA zone 10a-11b outdoors; grown as a houseplant or under glass elsewhere and RHS hardiness H1b (tender; indoor or heated greenhouse in the UK, can summer outdoors above ~12°C). Outside that range it must come indoors before the first frost — treat any outdoor stint as a summer holiday, not a permanent home.
More crossandra (firecracker flower) care
In the UK? Keeping crossandra (firecracker flower) warm in a UK home covers the radiator, single-glazing and heating-season humidity angle. Temperature and humidity are one piece. See the full crossandra (firecracker flower) care guide, its cold-hardiness guide, and watering schedule — humidity and watering problems are easy to confuse.