Plant care
Herald's Trumpettemperature & humidity
Beaumontia grandiflora
More about herald's trumpet
Ideal temperature for herald's trumpet
Herald's Trumpet is comfortable in any room a person is comfortable in, roughly 10-32°C (50-90°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
Herald's Trumpet is frost-tender (USDA 9b-12, 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 herald's trumpet
Herald's Trumpet sits happiest at around 50-75% relative humidity. Tolerates the moderate humidity of its subtropical mountain origin. Indoor specimens appreciate 50-65% RH; below 40% causes leaf tip browning. Outdoors in warm climates, natural humidity is usually sufficient. In dry conservatories, pebble trays or humidifiers near the plant help maintain adequate moisture around the foliage. 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.
Herald's Trumpet temperature & humidity — frequently asked questions
What temperature is best for herald's trumpet?
Herald's Trumpet grows best between 10-32°C (50-90°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 herald's trumpet tolerate?
Herald's Trumpet 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 herald's trumpet need?
Herald's Trumpet prefers about 50-75% relative humidity. Tolerates the moderate humidity of its subtropical mountain origin. Indoor specimens appreciate 50-65% RH; below 40% causes leaf tip browning. Outdoors in warm climates, natural humidity is usually sufficient. In dry conservatories, pebble trays or humidifiers near the plant help maintain adequate moisture around the foliage.
How do I raise humidity for herald's trumpet?
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 herald's trumpet live outside?
Herald's Trumpet is rated for USDA zone 9b-12 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 herald's trumpet care
In the UK? Keeping herald's trumpet warm in a UK home covers the radiator, single-glazing and heating-season humidity angle. Temperature and humidity are one piece. See the full herald's trumpet care guide, its cold-hardiness guide, and watering schedule — humidity and watering problems are easy to confuse.