Plant care
Bok Choy 'Black Summer'temperature & humidity
Brassica rapa var. chinensis 'Black Summer'
More about bok choy 'black summer'
Ideal temperature for bok choy 'black summer'
Temperature kills fewer bok choy 'black summer' 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
Bok Choy 'Black Summer' is comparatively hardy (USDA Grown as a cool-season annual in zones 2-11, RHS H4). 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 bok choy 'black summer'
Bok Choy 'Black Summer' sits happiest at around Ambient outdoor relative humidity. A field and container vegetable with no special humidity requirement; airy spacing reduces downy mildew and rot in damp conditions. 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.
Bok Choy 'Black Summer' temperature & humidity — frequently asked questions
What temperature is best for bok choy 'black summer'?
Bok Choy 'Black Summer' 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 bok choy 'black summer' tolerate?
Bok Choy 'Black Summer' starts to suffer below roughly 13°C. It tolerates a cold dormant period within USDA Grown as a cool-season annual in zones 2-11, but a wet cold root zone is more dangerous than cold air.
What humidity does bok choy 'black summer' need?
Bok Choy 'Black Summer' prefers about Ambient outdoor relative humidity. A field and container vegetable with no special humidity requirement; airy spacing reduces downy mildew and rot in damp conditions.
How do I raise humidity for bok choy 'black summer'?
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 bok choy 'black summer' live outside?
Bok Choy 'Black Summer' is rated for USDA zone Grown as a cool-season annual in zones 2-11 and RHS hardiness H4. 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 bok choy 'black summer' care
In the UK? Keeping bok choy 'black summer' warm in a UK home covers the radiator, single-glazing and heating-season humidity angle. Temperature and humidity are one piece. See the full bok choy 'black summer' care guide, its cold-hardiness guide, and watering schedule — humidity and watering problems are easy to confuse.