Cold hardiness & minimum temperature

Is Passiflora coccinea (Passiflora coccinea)cold hardy? Hardiness zone & min temp

Also called red passionflower, scarlet passionflower.

More about passiflora coccinea

About Passiflora coccinea

Passiflora coccinea · also called red passionflower, scarlet passionflower · tropical

Passiflora coccinea is a vigorous tropical climbing vine prized for vivid scarlet, fringed flowers borne through the warm months. Native to South America, it climbs by tendrils and needs sturdy support, ample warmth and high humidity. In cool climates it is grown under glass or as a conservatory specimen, flowering best in bright, frost-free conditions with steady moisture.

Cold limit: USDA 10-12 (frost-tender; grown under glass elsewhere) · RHS H1c (16-27°C)

Watch for — Leaf yellowing and drop: Often cold draughts, overwatering or sudden temperature swings; keep the plant warm and let the surface dry slightly between waterings.

What passiflora coccinea's hardiness rating actually means

Passiflora coccinea 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 10-12 (frost-tender; grown under glass 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). Passiflora coccinea has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

Concretely, for passiflora coccinea 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 passiflora coccinea 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 passiflora coccinea can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H1c figure above.

Passiflora coccinea hardiness — frequently asked questions

Is passiflora coccinea cold hardy?

Passiflora coccinea 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. Passiflora coccinea can only live outside year-round in genuinely frost-free climates (roughly USDA 10-12 (frost-tender; grown under glass elsewhere)); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature passiflora coccinea can survive?

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

What hardiness zone is passiflora coccinea?

Passiflora coccinea is rated USDA 10-12 (frost-tender; grown under glass elsewhere) and RHS H1c — Warm-temperate — can summer outdoors but must come in well before the first frost.

Can passiflora coccinea 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 passiflora coccinea 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.