Cold hardiness & minimum temperature

Is Rose grape (Medinilla magnifica)cold hardy? Hardiness zone & min temp

Also called Rose grape, Showy medinilla, Pink lantern, Philippine orchid, Malaysian orchid.

More about rose grape

About Rose grape

Medinilla magnifica · also called Rose grape, Showy medinilla · flowering

Rose grape (Medinilla magnifica) is a showy tropical shrub from the Philippines grown for cascading pink flower panicles above large ribbed leaves. It demands bright indirect light, warmth above 15C, and consistently high humidity, plus a cool winter rest to rebloom. Not ASPCA-listed, so treat as mildly toxic and keep away from pets.

Cold limit: USDA USDA 11-12 (RHS H1A) - frost-tender, indoor/greenhouse only (18-27C in growth; cool winter rest 15-18C)

Watch for — Failure to rebloom: The most common complaint. Flower buds form only after a cool, drier winter rest of roughly 8-12 weeks at 15-18C. Kept warm and well-watered year-round, the plant grows leaves but skips flowering.

What rose grape's hardiness rating actually means

Rose grape 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 H1b means: Sub-tropical — a normal warm home is fine, but it cannot go outside in a cool season. On the US scale that maps to USDA USDA 11-12 (RHS H1A) - frost-tender, indoor/greenhouse only — 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 10 °C (sustained cold below this is damaging). Rose grape has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

Concretely, for rose grape as it gets too cold:

Below about about 10 °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 rose grape go outside or overwinter — and where?

It can holiday outdoors in summer once nights are reliably above 10 °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 rose grape can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H1b figure above.

Rose grape hardiness — frequently asked questions

Is rose grape cold hardy?

Rose grape 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. Rose grape can only live outside year-round in genuinely frost-free climates (roughly USDA USDA 11-12 (RHS H1A) - frost-tender, indoor/greenhouse only); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature rose grape can survive?

Minimum survivable temperature is roughly about 10 °C (sustained cold below this is damaging). Rose grape has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

What hardiness zone is rose grape?

Rose grape is rated USDA USDA 11-12 (RHS H1A) - frost-tender, indoor/greenhouse only and RHS H1b — Sub-tropical — a normal warm home is fine, but it cannot go outside in a cool season.

Can rose grape survive winter outside?

It can holiday outdoors in summer once nights are reliably above 10 °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 rose grape below its minimum temperature?

Below about about 10 °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.