Plant care
Thornless Evergreen Blackberrytemperature & humidity
Rubus laciniatus 'Thornless Evergreen'
More about thornless evergreen blackberry
Ideal temperature for thornless evergreen blackberry
Thornless Evergreen Blackberry is comfortable in any room a person is comfortable in, roughly -15 to 30°C (5 to 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 -15°C growth pauses; cold beyond that pushes it into dormancy rather than killing it outright.
Cold tolerance & winter care
Thornless Evergreen Blackberry is comparatively hardy (USDA 6-9, RHS H5). 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 thornless evergreen blackberry
Thornless Evergreen Blackberry sits happiest at around 40-60% relative humidity. Tolerant of ambient outdoor humidity. As with all cane fruit, airflow through the canes matters more than humidity, preventing fruit rot and fungal cane disease in damp weather. 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.
Thornless Evergreen Blackberry temperature & humidity — frequently asked questions
What temperature is best for thornless evergreen blackberry?
Thornless Evergreen Blackberry grows best between -15 to 30°C (5 to 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 thornless evergreen blackberry tolerate?
Thornless Evergreen Blackberry starts to suffer below roughly -15°C. It tolerates a cold dormant period within USDA 6-9, but a wet cold root zone is more dangerous than cold air.
What humidity does thornless evergreen blackberry need?
Thornless Evergreen Blackberry prefers about 40-60% relative humidity. Tolerant of ambient outdoor humidity. As with all cane fruit, airflow through the canes matters more than humidity, preventing fruit rot and fungal cane disease in damp weather.
How do I raise humidity for thornless evergreen blackberry?
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 thornless evergreen blackberry live outside?
Thornless Evergreen Blackberry is rated for USDA zone 6-9 and RHS hardiness H5. 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 thornless evergreen blackberry care
In the UK? Keeping thornless evergreen blackberry warm in a UK home covers the radiator, single-glazing and heating-season humidity angle. Temperature and humidity are one piece. See the full thornless evergreen blackberry care guide, its cold-hardiness guide, and watering schedule — humidity and watering problems are easy to confuse.