Plant care
Napa Cabbage 'Blues'temperature & humidity
Brassica rapa var. pekinensis 'Blues'
More about napa cabbage 'blues'
Ideal temperature for napa cabbage 'blues'
Temperature kills fewer napa cabbage 'blues' 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 13-24°C (55-75°F) is fine; the spot you put the plant in matters more. Below roughly 13°C growth pauses; cold beyond that pushes it into dormancy rather than killing it outright.
Cold tolerance & winter care
Napa Cabbage 'Blues' is comparatively hardy (USDA Cool-season annual, zones 4-11; bolt tolerance widens its sowing window, tolerates light frost, RHS H4 (hardy through most winters as a crop; grown as an annual)). 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 napa cabbage 'blues'
Napa Cabbage 'Blues' sits happiest at around 50-70% relative humidity. Outdoor crop responsive to soil moisture rather than air humidity. Space heads for airflow; persistent leaf wetness encourages bacterial soft rot and mildews. 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.
Napa Cabbage 'Blues' temperature & humidity — frequently asked questions
What temperature is best for napa cabbage 'blues'?
Napa Cabbage 'Blues' grows best between 13-24°C (55-75°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 napa cabbage 'blues' tolerate?
Napa Cabbage 'Blues' starts to suffer below roughly 13°C. It tolerates a cold dormant period within USDA Cool-season annual, zones 4-11; bolt tolerance widens its sowing window, tolerates light frost, but a wet cold root zone is more dangerous than cold air.
What humidity does napa cabbage 'blues' need?
Napa Cabbage 'Blues' prefers about 50-70% relative humidity. Outdoor crop responsive to soil moisture rather than air humidity. Space heads for airflow; persistent leaf wetness encourages bacterial soft rot and mildews.
How do I raise humidity for napa cabbage 'blues'?
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 napa cabbage 'blues' live outside?
Napa Cabbage 'Blues' is rated for USDA zone Cool-season annual, zones 4-11; bolt tolerance widens its sowing window, tolerates light frost and RHS hardiness H4 (hardy through most winters as a crop; grown as an annual). 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 napa cabbage 'blues' care
In the UK? Keeping napa cabbage 'blues' warm in a UK home covers the radiator, single-glazing and heating-season humidity angle. Temperature and humidity are one piece. See the full napa cabbage 'blues' care guide, its cold-hardiness guide, and watering schedule — humidity and watering problems are easy to confuse.