Plant care
Bradley's Spleenworttemperature & humidity
Asplenium bradleyi
More about bradley's spleenwort
Ideal temperature for bradley's spleenwort
Temperature kills fewer bradley's spleenwort 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 -18 to 26 °C (0 to 79 °F) is fine; the spot you put the plant in matters more. Below roughly -18°C growth pauses; cold beyond that pushes it into dormancy rather than killing it outright.
Cold tolerance & winter care
Bradley's Spleenwort is comparatively hardy (USDA 5-8, 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 bradley's spleenwort
Bradley's Spleenwort sits happiest at around 50–75 % relative humidity. Moderate humidity suits this fern in a shaded, sheltered rock garden. When grown in a container or indoors, stand the pot on a pebble-and-water tray and avoid placing near heat sources. 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.
Bradley's Spleenwort temperature & humidity — frequently asked questions
What temperature is best for bradley's spleenwort?
Bradley's Spleenwort grows best between -18 to 26 °C (0 to 79 °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 bradley's spleenwort tolerate?
Bradley's Spleenwort starts to suffer below roughly -18°C. It tolerates a cold dormant period within USDA 5-8, but a wet cold root zone is more dangerous than cold air.
What humidity does bradley's spleenwort need?
Bradley's Spleenwort prefers about 50–75 % relative humidity. Moderate humidity suits this fern in a shaded, sheltered rock garden. When grown in a container or indoors, stand the pot on a pebble-and-water tray and avoid placing near heat sources.
How do I raise humidity for bradley's spleenwort?
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 bradley's spleenwort live outside?
Bradley's Spleenwort is rated for USDA zone 5-8 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 bradley's spleenwort care
In the UK? Keeping bradley's spleenwort warm in a UK home covers the radiator, single-glazing and heating-season humidity angle. Temperature and humidity are one piece. See the full bradley's spleenwort care guide, its cold-hardiness guide, and watering schedule — humidity and watering problems are easy to confuse.