Plant care
Genovese Basiltemperature & humidity
Ocimum basilicum 'Genovese'
More about genovese basil
Ideal temperature for genovese basil
Genovese Basil is comfortable in any room a person is comfortable in, roughly 18-30°C (65-86°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
Genovese Basil is frost-tender (USDA Tender annual; grown outdoors in zones 4-11 after frost, year-round indoors, RHS H1c (tender; killed by frost, protect below ~10°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 genovese basil
Genovese Basil sits happiest at around 40-60% relative humidity. Enjoys warm, moderately humid air but tolerates average indoor levels. Good airflow is more important than high humidity, as still, damp conditions encourage downy mildew and grey mould on the leaves. 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.
Genovese Basil temperature & humidity — frequently asked questions
What temperature is best for genovese basil?
Genovese Basil grows best between 18-30°C (65-86°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 genovese basil tolerate?
Genovese Basil 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 genovese basil need?
Genovese Basil prefers about 40-60% relative humidity. Enjoys warm, moderately humid air but tolerates average indoor levels. Good airflow is more important than high humidity, as still, damp conditions encourage downy mildew and grey mould on the leaves.
How do I raise humidity for genovese basil?
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 genovese basil live outside?
Genovese Basil is rated for USDA zone Tender annual; grown outdoors in zones 4-11 after frost, year-round indoors and RHS hardiness H1c (tender; killed by frost, protect below ~10°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 genovese basil care
In the UK? Keeping genovese basil warm in a UK home covers the radiator, single-glazing and heating-season humidity angle. Temperature and humidity are one piece. See the full genovese basil care guide, its cold-hardiness guide, and watering schedule — humidity and watering problems are easy to confuse.