UK hardiness
Is Queen of the Night Cereus hardy in the UK?
Cereus hildmannianus
More about queen of the night cereus in the UK
Queen of the Night Cereus and the RHS hardiness rating
Queen of the Night Cereus is rated RHS H2 — tender, meaning it withstands winter minimums of about 1 to 5°C. In practice that means it needs a frost-free greenhouse or indoors over winter — a UK frost will kill it. 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 queen of the night cereus USDA hardiness guide.
Does UK region change it?
Because queen of the night cereus 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 queen of the night cereus in the UK
Overwintering queen of the night cereus 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.
Queen of the Night Cereus UK hardiness — frequently asked questions
Is queen of the night cereus hardy in the UK?
Queen of the Night Cereus is rated RHS H2 (tender, hardy to about 1 to 5°C). It is not winter-hardy anywhere in the UK and must be overwintered under cover.
Can queen of the night cereus stay outside over winter in the UK?
No. Queen of the Night Cereus 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 H2 mean?
RHS hardiness ratings run H1a (needs a heated glasshouse) to H7 (survives below -20°C). Queen of the Night Cereus's rating, H2, means tender — it tolerates winter minimums of about 1 to 5°C. The rating is an absolute minimum, not an average.
How do I overwinter queen of the night cereus in the UK?
Overwintering queen of the night cereus 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 queen of the night cereus survives?
Because queen of the night cereus 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 queen of the night cereus care
See the full queen of the night cereus care guide, its temperature & humidity needs, and the US (USDA) hardiness version of this page.