Cold hardiness & minimum temperature

Is Bougainvillea 'Raspberry Ice' (Bougainvillea 'Raspberry Ice')cold hardy? Hardiness zone & min temp

Also called Variegated Bougainvillea.

More about bougainvillea 'raspberry ice'

About Bougainvillea 'Raspberry Ice'

Bougainvillea 'Raspberry Ice' · also called Variegated Bougainvillea · flowering

Bougainvillea 'Raspberry Ice' is a compact, mounding cultivar grown as much for its cream-edged variegated foliage as for its rich raspberry-pink bracts. Lower and more cascading than climbing types, it suits hanging baskets, low walls, and containers. Like all bougainvilleas it craves full sun, lean fast-draining soil, and slightly dry roots to flower well, and is frost-tender.

Cold limit: USDA 9-11 (frost-tender; container culture and overwintering indoors elsewhere) · RHS H1c (18-30°C)

Watch for — Frost damage: Tender to cold; protect or bring indoors below about 2°C and prune blackened growth in spring.

What bougainvillea 'raspberry ice''s hardiness rating actually means

Bougainvillea 'Raspberry Ice' is not cold hardy. It is a tropical houseplant that dies if it is left out through frost — there is no zone where it overwinters outdoors in a UK or cold-US climate. Its RHS rating of H1c means: Warm-temperate — can summer outdoors but must come in well before the first frost. On the US scale that maps to USDA 9-11 (frost-tender; container culture and overwintering indoors elsewhere) — the zones where it can be left outdoors year-round.

New to these scales? The USDA hardiness zone map explained covers how the zone numbers work, and you can find your own zone with the zone finder.

Minimum temperature — and what happens below it

Minimum survivable temperature is roughly about 5 °C (and never frost). Bougainvillea 'Raspberry Ice' has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

Concretely, for bougainvillea 'raspberry ice' as it gets too cold:

Below about about 5 °C, growth stalls and the leaves start to show cold stress — dark, water-soaked, or yellowing patches.
A single light frost blackens the foliage; a hard freeze kills the whole plant, roots included, and it does not recover.
Even a cold, draughty windowsill or an unheated porch in winter can be enough to damage it permanently.

Can bougainvillea 'raspberry ice' go outside or overwinter — and where?

It can holiday outdoors in summer once nights are reliably above 5 °C, in shade or dappled light, hardened off gradually.
Bring it back indoors well before the first autumn frost — do not wait for a frost warning, move it when nights drop toward 10-12 °C.
It will never overwinter outside in a temperate climate; the indoors is its winter home, full stop.

Work back from your local frost dates with the frost-date calculator: the last spring frost and first autumn frost are what really decide when bougainvillea 'raspberry ice' can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H1c figure above.

Bougainvillea 'Raspberry Ice' hardiness — frequently asked questions

Is bougainvillea 'raspberry ice' cold hardy?

Bougainvillea 'Raspberry Ice' is not cold hardy. It is a tropical houseplant that dies if it is left out through frost — there is no zone where it overwinters outdoors in a UK or cold-US climate. Indoor-only in almost every home. Bougainvillea 'Raspberry Ice' can only live outside year-round in genuinely frost-free climates (roughly USDA 9-11 (frost-tender; container culture and overwintering indoors elsewhere)); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature bougainvillea 'raspberry ice' can survive?

Minimum survivable temperature is roughly about 5 °C (and never frost). Bougainvillea 'Raspberry Ice' has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

What hardiness zone is bougainvillea 'raspberry ice'?

Bougainvillea 'Raspberry Ice' is rated USDA 9-11 (frost-tender; container culture and overwintering indoors elsewhere) and RHS H1c — Warm-temperate — can summer outdoors but must come in well before the first frost.

Can bougainvillea 'raspberry ice' survive winter outside?

It can holiday outdoors in summer once nights are reliably above 5 °C, in shade or dappled light, hardened off gradually. Bring it back indoors well before the first autumn frost — do not wait for a frost warning, move it when nights drop toward 10-12 °C. It will never overwinter outside in a temperate climate; the indoors is its winter home, full stop.

What happens to bougainvillea 'raspberry ice' below its minimum temperature?

Below about about 5 °C, growth stalls and the leaves start to show cold stress — dark, water-soaked, or yellowing patches. A single light frost blackens the foliage; a hard freeze kills the whole plant, roots included, and it does not recover. Even a cold, draughty windowsill or an unheated porch in winter can be enough to damage it permanently.