UK hardiness
Is Stilt Palm hardy in the UK?
Iriartea deltoidea
More about stilt palm in the UK
Stilt Palm and the RHS hardiness rating
Stilt Palm is rated RHS H1A — heated glasshouse — tropical, meaning it withstands winter minimums of about above 15°C. In practice that means it cannot live outdoors in the UK at any time; a warm indoor room or heated glasshouse only. 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 stilt palm USDA hardiness guide.
Does UK region change it?
Because stilt palm 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 stilt palm in the UK
Overwintering stilt palm 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.
Stilt Palm UK hardiness — frequently asked questions
Is stilt palm hardy in the UK?
Stilt Palm is rated RHS H1A (heated glasshouse — tropical, hardy to about above 15°C). It is not winter-hardy anywhere in the UK and must be overwintered under cover.
Can stilt palm stay outside over winter in the UK?
No. Stilt Palm 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 H1A mean?
RHS hardiness ratings run H1a (needs a heated glasshouse) to H7 (survives below -20°C). Stilt Palm's rating, H1A, means heated glasshouse — tropical — it tolerates winter minimums of about above 15°C. The rating is an absolute minimum, not an average.
How do I overwinter stilt palm in the UK?
Overwintering stilt palm 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 stilt palm survives?
Because stilt palm 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 stilt palm care
See the full stilt palm care guide, its temperature & humidity needs, and the US (USDA) hardiness version of this page.