Plant care
Kohlrabi 'Kossak'temperature & humidity
Brassica oleracea var. gongylodes 'Kossak'
More about kohlrabi 'kossak'
Ideal temperature for kohlrabi 'kossak'
Temperature kills fewer kohlrabi 'kossak' plants than you'd think. What kills them is the micro-climate within a normal-temperature room — a leaf pressed against single-glazed winter glass, the hot dry updraft directly above a radiator, the cold blast from an AC vent. The thermostat reading at 10-24°C (50-75°F) is fine; the spot you put the plant in matters more. Below roughly 10°C growth pauses; cold beyond that pushes it into dormancy rather than killing it outright.
Cold tolerance & winter care
Kohlrabi 'Kossak' is comparatively hardy (USDA Cool-season annual in zones 3-11; mature bulbs tolerate light frost and store well, RHS H4 (mature plants hardy to roughly -10°C; good for autumn/winter storage)). Within that range it tolerates a cold dormant spell outdoors; outside it, grow it in a container you can move under cover or overwinter in a cool but frost-free spot. Hardiness assumes an established plant in well-drained soil — a wet, cold root zone kills far more plants than cold air alone.
Humidity for kohlrabi 'kossak'
Kohlrabi 'Kossak' sits happiest at around 40-70% relative humidity. Outdoor crop unaffected by air humidity; even soil moisture matters most. Good spacing reduces fungal leaf disease. 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.
Kohlrabi 'Kossak' temperature & humidity — frequently asked questions
What temperature is best for kohlrabi 'kossak'?
Kohlrabi 'Kossak' grows best between 10-24°C (50-75°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 kohlrabi 'kossak' tolerate?
Kohlrabi 'Kossak' starts to suffer below roughly 10°C. It tolerates a cold dormant period within USDA Cool-season annual in zones 3-11; mature bulbs tolerate light frost and store well, but a wet cold root zone is more dangerous than cold air.
What humidity does kohlrabi 'kossak' need?
Kohlrabi 'Kossak' prefers about 40-70% relative humidity. Outdoor crop unaffected by air humidity; even soil moisture matters most. Good spacing reduces fungal leaf disease.
How do I raise humidity for kohlrabi 'kossak'?
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 kohlrabi 'kossak' live outside?
Kohlrabi 'Kossak' is rated for USDA zone Cool-season annual in zones 3-11; mature bulbs tolerate light frost and store well and RHS hardiness H4 (mature plants hardy to roughly -10°C; good for autumn/winter storage). Within that range it can stay outdoors; outside it, grow it in a moveable container and protect the roots from a wet, cold winter.
More kohlrabi 'kossak' care
In the UK? Keeping kohlrabi 'kossak' warm in a UK home covers the radiator, single-glazing and heating-season humidity angle. Temperature and humidity are one piece. See the full kohlrabi 'kossak' care guide, its cold-hardiness guide, and watering schedule — humidity and watering problems are easy to confuse.