Plant care
Hammock Ferntemperature & humidity
Blechnum occidentale
More about hammock fern
Ideal temperature for hammock fern
Hammock Fern is comfortable in any room a person is comfortable in, roughly 16–28 °C (61–82 °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 16°C the damage starts — soft blackened patches, translucent leaves, sometimes overnight.
Cold tolerance & winter care
Hammock Fern is frost-tender (USDA 9–11, RHS H1c). It cannot survive a frost, so in most of the US and UK it lives indoors year-round or summers outside and comes back in well before the first autumn frost — once nights drop toward 10-12°C is the cue, not the first frost warning. Acclimate it over a week when moving between indoors and out so the leaves do not shock.
Humidity for hammock fern
Hammock Fern sits happiest at around 50–75% relative humidity. Prefers moderate to high humidity. More tolerant of average indoor humidity than many tropical ferns, but still benefits from additional moisture. Use a pebble tray or humidifier in centrally heated rooms. Avoid positioning near radiators or air-conditioning vents. 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.
Hammock Fern temperature & humidity — frequently asked questions
What temperature is best for hammock fern?
Hammock Fern grows best between 16–28 °C (61–82 °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 hammock fern tolerate?
Hammock Fern starts to suffer below roughly 16°C. It is frost-tender and will be damaged or killed by a frost, so bring it indoors once nights fall toward 10-12°C.
What humidity does hammock fern need?
Hammock Fern prefers about 50–75% relative humidity. Prefers moderate to high humidity. More tolerant of average indoor humidity than many tropical ferns, but still benefits from additional moisture. Use a pebble tray or humidifier in centrally heated rooms. Avoid positioning near radiators or air-conditioning vents.
How do I raise humidity for hammock fern?
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 hammock fern live outside?
Hammock Fern is rated for USDA zone 9–11 and RHS hardiness H1c. Outside that range it must come indoors before the first frost — treat any outdoor stint as a summer holiday, not a permanent home.
More hammock fern care
In the UK? Keeping hammock fern warm in a UK home covers the radiator, single-glazing and heating-season humidity angle. Temperature and humidity are one piece. See the full hammock fern care guide, its cold-hardiness guide, and watering schedule — humidity and watering problems are easy to confuse.