Plant care
Marsilea quadrifoliatemperature & humidity
Marsilea quadrifolia
More about marsilea quadrifolia
Ideal temperature for marsilea quadrifolia
Aim for 15-26°C (59-79°F) on the thermostat and you've handled the easy part. The hard part is the half-metre around the plant: window glass that drops to near-freezing on a January night, a radiator pumping out hot dry air, a draught from an opened front door. Move the plant 30 cm and you've usually fixed the problem. Below roughly 15°C growth pauses; cold beyond that pushes it into dormancy rather than killing it outright.
Cold tolerance & winter care
Marsilea quadrifolia is comparatively hardy (USDA 6-10 (hardy as a pond marginal where the rhizome does not freeze solid), 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 marsilea quadrifolia
Marsilea quadrifolia sits happiest at around 70-100% relative humidity. An aquatic and marginal plant where the leaves sit on or just above water, so atmospheric humidity is essentially irrelevant as long as the roots stay wet. No misting is required; submerged forms are governed by water quality. 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.
Marsilea quadrifolia temperature & humidity — frequently asked questions
What temperature is best for marsilea quadrifolia?
Marsilea quadrifolia grows best between 15-26°C (59-79°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 marsilea quadrifolia tolerate?
Marsilea quadrifolia starts to suffer below roughly 15°C. It tolerates a cold dormant period within USDA 6-10 (hardy as a pond marginal where the rhizome does not freeze solid), but a wet cold root zone is more dangerous than cold air.
What humidity does marsilea quadrifolia need?
Marsilea quadrifolia prefers about 70-100% relative humidity. An aquatic and marginal plant where the leaves sit on or just above water, so atmospheric humidity is essentially irrelevant as long as the roots stay wet. No misting is required; submerged forms are governed by water quality.
How do I raise humidity for marsilea quadrifolia?
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 marsilea quadrifolia live outside?
Marsilea quadrifolia is rated for USDA zone 6-10 (hardy as a pond marginal where the rhizome does not freeze solid) 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 marsilea quadrifolia care
In the UK? Keeping marsilea quadrifolia warm in a UK home covers the radiator, single-glazing and heating-season humidity angle. Temperature and humidity are one piece. See the full marsilea quadrifolia care guide, its cold-hardiness guide, and watering schedule — humidity and watering problems are easy to confuse.