Plant care
Jeddeloh Hemlocktemperature & humidity
Tsuga canadensis 'Jeddeloh'
More about jeddeloh hemlock
Ideal temperature for jeddeloh hemlock
Temperature kills fewer jeddeloh hemlock 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 -30°C to 25°C (-22°F to 77°F) is fine; the spot you put the plant in matters more. Below roughly -30°C growth pauses; cold beyond that pushes it into dormancy rather than killing it outright.
Cold tolerance & winter care
Jeddeloh Hemlock is comparatively hardy (USDA 4-7, 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 jeddeloh hemlock
Jeddeloh Hemlock sits happiest at around Moderate to high (50–70%) relative humidity. Benefits from higher atmospheric humidity; in dry or windy sites, erect a temporary hessian windbreak for the first two winters and ensure the root zone never dries completely. 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.
Jeddeloh Hemlock temperature & humidity — frequently asked questions
What temperature is best for jeddeloh hemlock?
Jeddeloh Hemlock grows best between -30°C to 25°C (-22°F to 77°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 jeddeloh hemlock tolerate?
Jeddeloh Hemlock starts to suffer below roughly -30°C. It tolerates a cold dormant period within USDA 4-7, but a wet cold root zone is more dangerous than cold air.
What humidity does jeddeloh hemlock need?
Jeddeloh Hemlock prefers about Moderate to high (50–70%) relative humidity. Benefits from higher atmospheric humidity; in dry or windy sites, erect a temporary hessian windbreak for the first two winters and ensure the root zone never dries completely.
How do I raise humidity for jeddeloh hemlock?
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 jeddeloh hemlock live outside?
Jeddeloh Hemlock is rated for USDA zone 4-7 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 jeddeloh hemlock care
In the UK? Keeping jeddeloh hemlock warm in a UK home covers the radiator, single-glazing and heating-season humidity angle. Temperature and humidity are one piece. See the full jeddeloh hemlock care guide, its cold-hardiness guide, and watering schedule — humidity and watering problems are easy to confuse.