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Plant care

Mimulus ringenstemperature & humidity

Mimulus ringens

RHS H6USDA 3-9Mildly toxic to pets

More about mimulus ringens

Ideal temperature for mimulus ringens

Mimulus ringens is comfortable in any room a person is comfortable in, roughly 5-28°C (41-82°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 5°C growth pauses; cold beyond that pushes it into dormancy rather than killing it outright.

Cold tolerance & winter care

Mimulus ringens is comparatively hardy (USDA 3-9, RHS H6). 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 mimulus ringens

Mimulus ringens sits happiest at around 60-100% relative humidity. An outdoor wetland species suited to the high humidity of pond and marsh margins. Air humidity is not a limiting factor; permanent root-zone wetness is what it requires. 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.

Mimulus ringens temperature & humidity — frequently asked questions

What temperature is best for mimulus ringens?

Mimulus ringens grows best between 5-28°C (41-82°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 mimulus ringens tolerate?

Mimulus ringens starts to suffer below roughly 5°C. It tolerates a cold dormant period within USDA 3-9, but a wet cold root zone is more dangerous than cold air.

What humidity does mimulus ringens need?

Mimulus ringens prefers about 60-100% relative humidity. An outdoor wetland species suited to the high humidity of pond and marsh margins. Air humidity is not a limiting factor; permanent root-zone wetness is what it requires.

How do I raise humidity for mimulus ringens?

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 mimulus ringens live outside?

Mimulus ringens is rated for USDA zone 3-9 and RHS hardiness H6. 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 mimulus ringens care

In the UK? Keeping mimulus ringens warm in a UK home covers the radiator, single-glazing and heating-season humidity angle. Temperature and humidity are one piece. See the full mimulus ringens care guide, its cold-hardiness guide, and watering schedule — humidity and watering problems are easy to confuse.