Plant care
Rheingold Arborvitaetemperature & humidity
Thuja occidentalis 'Rheingold'
More about rheingold arborvitae
Ideal temperature for rheingold arborvitae
Aim for -37 to 30°C (-35 to 86°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 -37°C growth pauses; cold beyond that pushes it into dormancy rather than killing it outright.
Cold tolerance & winter care
Rheingold Arborvitae is comparatively hardy (USDA 2-8 (amber dwarf conifer), RHS H7). 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 rheingold arborvitae
Rheingold Arborvitae sits happiest at around Ambient outdoor humidity relative humidity. An outdoor dwarf conifer unaffected by humidity; allow airflow to limit fungal foliage problems in damp, crowded conditions. 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.
Rheingold Arborvitae temperature & humidity — frequently asked questions
What temperature is best for rheingold arborvitae?
Rheingold Arborvitae grows best between -37 to 30°C (-35 to 86°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 rheingold arborvitae tolerate?
Rheingold Arborvitae starts to suffer below roughly -37°C. It tolerates a cold dormant period within USDA 2-8 (amber dwarf conifer), but a wet cold root zone is more dangerous than cold air.
What humidity does rheingold arborvitae need?
Rheingold Arborvitae prefers about Ambient outdoor humidity relative humidity. An outdoor dwarf conifer unaffected by humidity; allow airflow to limit fungal foliage problems in damp, crowded conditions.
How do I raise humidity for rheingold arborvitae?
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 rheingold arborvitae live outside?
Rheingold Arborvitae is rated for USDA zone 2-8 (amber dwarf conifer) and RHS hardiness H7. 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 rheingold arborvitae care
In the UK? Keeping rheingold arborvitae warm in a UK home covers the radiator, single-glazing and heating-season humidity angle. Temperature and humidity are one piece. See the full rheingold arborvitae care guide, its cold-hardiness guide, and watering schedule — humidity and watering problems are easy to confuse.