UK hardiness
Is Warming's Sinningia hardy in the UK?
Sinningia warmingii
More about warming's sinningia in the UK
Warming's Sinningia and the RHS hardiness rating
Warming's Sinningia is rated RHS H1c — warm temperate, meaning it withstands winter minimums of about 5 to 10°C. In practice that means it fine outdoors through most UK summers but must come in before the first frost. The RHS rating describes an absolute minimum temperature, not an average: a single hard frost below its band is what does the damage, so the question is always "what is the coldest night my garden gets?", not "what is a typical winter here?".
This follows the RHS plant hardiness rating system (H1a–H7), the UK standard. For the US growing-zone view, see the warming's sinningia USDA hardiness guide.
Does UK region change it?
Because warming's sinningia is frost-tender, UK region matters less than the simple rule: it does not stay outdoors over winter anywhere in the UK. Treat any time outside as a summer holiday — bring it back indoors once nights drop toward 10°C, well before the first frost, and acclimatise it over a week each way so the leaves do not shock.
Overwintering warming's sinningia in the UK
Overwintering warming's sinningia in the UK means bringing it in: a bright, frost-free room or a heated glasshouse, watered sparingly while growth slows. Do not leave it against cold glass or near an unheated porch. Move it back out only after the last spring frost has passed for your area.
Warming's Sinningia UK hardiness — frequently asked questions
Is warming's sinningia hardy in the UK?
Warming's Sinningia is rated RHS H1c (warm temperate, hardy to about 5 to 10°C). It is not winter-hardy anywhere in the UK and must be overwintered under cover.
Can warming's sinningia stay outside over winter in the UK?
No. Warming's Sinningia is frost-tender — a UK frost will kill it. Bring it indoors or into a frost-free greenhouse before the first autumn frost and return it outside only after the last spring frost.
What does RHS H1c mean?
RHS hardiness ratings run H1a (needs a heated glasshouse) to H7 (survives below -20°C). Warming's Sinningia's rating, H1c, means warm temperate — it tolerates winter minimums of about 5 to 10°C. The rating is an absolute minimum, not an average.
How do I overwinter warming's sinningia in the UK?
Overwintering warming's sinningia in the UK means bringing it in: a bright, frost-free room or a heated glasshouse, watered sparingly while growth slows. Do not leave it against cold glass or near an unheated porch. Move it back out only after the last spring frost has passed for your area.
Does UK region change whether warming's sinningia survives?
Because warming's sinningia is frost-tender, UK region matters less than the simple rule: it does not stay outdoors over winter anywhere in the UK. Treat any time outside as a summer holiday — bring it back indoors once nights drop toward 10°C, well before the first frost, and acclimatise it over a week each way so the leaves do not shock.
More warming's sinningia care
See the full warming's sinningia care guide, its temperature & humidity needs, and the US (USDA) hardiness version of this page.