Plant care
Persian Cucumbertemperature & humidity
Cucumis sativus 'Persian'
More about persian cucumber
Ideal temperature for persian cucumber
Persian Cucumber is comfortable in any room a person is comfortable in, roughly 20–30°C growing season; soil ≥18°C for germination (68–86°F growing season; soil ≥65°F for germination). 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 20°C the damage starts — soft blackened patches, translucent leaves, sometimes overnight.
Cold tolerance & winter care
Persian Cucumber is frost-tender (USDA 4-11, 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 persian cucumber
Persian Cucumber sits happiest at around 60–70% relative humidity. Performs best in moderate to moderately high humidity. Excessively low humidity causes water stress; excessively high humidity with poor airflow promotes powdery mildew and cucumber mosaic virus. Trellis plants to maximise airflow around 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.
Persian Cucumber temperature & humidity — frequently asked questions
What temperature is best for persian cucumber?
Persian Cucumber grows best between 20–30°C growing season; soil ≥18°C for germination (68–86°F growing season; soil ≥65°F for germination). 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 persian cucumber tolerate?
Persian Cucumber starts to suffer below roughly 20°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 persian cucumber need?
Persian Cucumber prefers about 60–70% relative humidity. Performs best in moderate to moderately high humidity. Excessively low humidity causes water stress; excessively high humidity with poor airflow promotes powdery mildew and cucumber mosaic virus. Trellis plants to maximise airflow around foliage.
How do I raise humidity for persian cucumber?
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 persian cucumber live outside?
Persian Cucumber is rated for USDA zone 4-11 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 persian cucumber care
In the UK? Keeping persian cucumber warm in a UK home covers the radiator, single-glazing and heating-season humidity angle. Temperature and humidity are one piece. See the full persian cucumber care guide, its cold-hardiness guide, and watering schedule — humidity and watering problems are easy to confuse.