Plant care
Polystichum setiferum 'Divisilobum'temperature & humidity
Polystichum setiferum 'Divisilobum'
More about polystichum setiferum 'divisilobum'
Ideal temperature for polystichum setiferum 'divisilobum'
Temperature kills fewer polystichum setiferum 'divisilobum' 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 -12 to 24°C (10 to 75°F) is fine; the spot you put the plant in matters more. Below roughly -12°C growth pauses; cold beyond that pushes it into dormancy rather than killing it outright.
Cold tolerance & winter care
Polystichum setiferum 'Divisilobum' is comparatively hardy (USDA 5-8 (hardy evergreen fern), 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 polystichum setiferum 'divisilobum'
Polystichum setiferum 'Divisilobum' sits happiest at around 50-70% relative humidity. An evergreen woodland fern happy in the moderate humidity of shaded borders. Its soft, divided fronds appreciate shelter from drying winds, which can brown the delicate segments. 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.
Polystichum setiferum 'Divisilobum' temperature & humidity — frequently asked questions
What temperature is best for polystichum setiferum 'divisilobum'?
Polystichum setiferum 'Divisilobum' grows best between -12 to 24°C (10 to 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 polystichum setiferum 'divisilobum' tolerate?
Polystichum setiferum 'Divisilobum' starts to suffer below roughly -12°C. It tolerates a cold dormant period within USDA 5-8 (hardy evergreen fern), but a wet cold root zone is more dangerous than cold air.
What humidity does polystichum setiferum 'divisilobum' need?
Polystichum setiferum 'Divisilobum' prefers about 50-70% relative humidity. An evergreen woodland fern happy in the moderate humidity of shaded borders. Its soft, divided fronds appreciate shelter from drying winds, which can brown the delicate segments.
How do I raise humidity for polystichum setiferum 'divisilobum'?
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 polystichum setiferum 'divisilobum' live outside?
Polystichum setiferum 'Divisilobum' is rated for USDA zone 5-8 (hardy evergreen fern) 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 polystichum setiferum 'divisilobum' care
In the UK? Keeping polystichum setiferum 'divisilobum' warm in a UK home covers the radiator, single-glazing and heating-season humidity angle. Temperature and humidity are one piece. See the full polystichum setiferum 'divisilobum' care guide, its cold-hardiness guide, and watering schedule — humidity and watering problems are easy to confuse.