Growli

Plant care

Glaucous Lampranthustemperature & humidity

Lampranthus glaucus

RHS H2USDA 9–11Mildly toxic to pets

More about glaucous lampranthus

Ideal temperature for glaucous lampranthus

Aim for 5–35°C (41–95°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 5°C the damage starts — soft blackened patches, translucent leaves, sometimes overnight.

Cold tolerance & winter care

Glaucous Lampranthus is frost-tender (USDA 9–11, 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 glaucous lampranthus

Glaucous Lampranthus sits happiest at around Low, 20–45% RH relative humidity. Adapted to dry, coastal South African habitats. Tolerates salt-laden sea air well. Avoid stagnant, humid conditions especially in winter, as these encourage grey mould and fungal rots. 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.

Glaucous Lampranthus temperature & humidity — frequently asked questions

What temperature is best for glaucous lampranthus?

Glaucous Lampranthus grows best between 5–35°C (41–95°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 glaucous lampranthus tolerate?

Glaucous Lampranthus starts to suffer below roughly 5°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 glaucous lampranthus need?

Glaucous Lampranthus prefers about Low, 20–45% RH relative humidity. Adapted to dry, coastal South African habitats. Tolerates salt-laden sea air well. Avoid stagnant, humid conditions especially in winter, as these encourage grey mould and fungal rots.

How do I raise humidity for glaucous lampranthus?

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 glaucous lampranthus live outside?

Glaucous Lampranthus is rated for USDA zone 9–11 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 glaucous lampranthus care

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