Plant care
Thalictrum delavayi 'Hewitt's Double'temperature & humidity
Thalictrum delavayi 'Hewitt's Double'
More about thalictrum delavayi 'hewitt's double'
Ideal temperature for thalictrum delavayi 'hewitt's double'
Thalictrum delavayi 'Hewitt's Double' is comfortable in any room a person is comfortable in, roughly -20 to 24°C (-4 to 75°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 -20°C growth pauses; cold beyond that pushes it into dormancy rather than killing it outright.
Cold tolerance & winter care
Thalictrum delavayi 'Hewitt's Double' is comparatively hardy (USDA 4-8 (cool-temperate perennial), 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 thalictrum delavayi 'hewitt's double'
Thalictrum delavayi 'Hewitt's Double' sits happiest at around Ambient outdoor relative humidity. An outdoor perennial with no special humidity needs; it naturally prefers the cool, sheltered, slightly damp microclimate of a woodland-edge or north-facing border. 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.
Thalictrum delavayi 'Hewitt's Double' temperature & humidity — frequently asked questions
What temperature is best for thalictrum delavayi 'hewitt's double'?
Thalictrum delavayi 'Hewitt's Double' grows best between -20 to 24°C (-4 to 75°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 thalictrum delavayi 'hewitt's double' tolerate?
Thalictrum delavayi 'Hewitt's Double' starts to suffer below roughly -20°C. It tolerates a cold dormant period within USDA 4-8 (cool-temperate perennial), but a wet cold root zone is more dangerous than cold air.
What humidity does thalictrum delavayi 'hewitt's double' need?
Thalictrum delavayi 'Hewitt's Double' prefers about Ambient outdoor relative humidity. An outdoor perennial with no special humidity needs; it naturally prefers the cool, sheltered, slightly damp microclimate of a woodland-edge or north-facing border.
How do I raise humidity for thalictrum delavayi 'hewitt's double'?
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 thalictrum delavayi 'hewitt's double' live outside?
Thalictrum delavayi 'Hewitt's Double' is rated for USDA zone 4-8 (cool-temperate perennial) 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 thalictrum delavayi 'hewitt's double' care
In the UK? Keeping thalictrum delavayi 'hewitt's double' warm in a UK home covers the radiator, single-glazing and heating-season humidity angle. Temperature and humidity are one piece. See the full thalictrum delavayi 'hewitt's double' care guide, its cold-hardiness guide, and watering schedule — humidity and watering problems are easy to confuse.