Cold hardiness & minimum temperature

Is Bleeding heart vine (Clerodendrum thomsoniae)cold hardy? Hardiness zone & min temp

Also called Bleeding heart vine, Glory bower, Glorybower, Bleeding glory bower, Tropical bleeding heart, Bag flower.

More about bleeding heart vine

About Bleeding heart vine

Clerodendrum thomsoniae · also called Bleeding heart vine, Glory bower · tropical

Bleeding heart vine (Clerodendrum thomsoniae) is a fast-growing tropical climber prized for crimson-and-white flowers. It wants bright indirect light, steady moisture, warmth and high humidity, plus a cool winter rest to rebloom. Not the same as toxic Dicentra. The genus is not ASPCA-listed and reported mildly toxic, so keep it away from pets.

Cold limit: USDA USDA 10-12 (RHS hardiness H1B; grow as a tender houseplant or summer patio plant in cooler climates, bringing it in before temperatures fall below ~10 C / 50 F) (18-29 C (cool winter rest ~13-16 C))

Watch for — No flowers: Almost always caused by skipping the cool winter rest. A spell at roughly 13-16 C with reduced watering and no feed is what triggers flower-bud formation for the next season. Too little light also suppresses blooming.

What bleeding heart vine's hardiness rating actually means

Bleeding heart vine 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 USDA 10-12 (RHS hardiness H1B; grow as a tender houseplant or summer patio plant in cooler climates, bringing it in before temperatures fall below ~10 C / 50 F) — 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). Bleeding heart vine has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

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

Bleeding heart vine hardiness — frequently asked questions

Is bleeding heart vine cold hardy?

Bleeding heart vine 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. Bleeding heart vine can only live outside year-round in genuinely frost-free climates (roughly USDA USDA 10-12 (RHS hardiness H1B; grow as a tender houseplant or summer patio plant in cooler climates, bringing it in before temperatures fall below ~10 C / 50 F)); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature bleeding heart vine can survive?

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

What hardiness zone is bleeding heart vine?

Bleeding heart vine is rated USDA USDA 10-12 (RHS hardiness H1B; grow as a tender houseplant or summer patio plant in cooler climates, bringing it in before temperatures fall below ~10 C / 50 F) and RHS H1c — Warm-temperate — can summer outdoors but must come in well before the first frost.

Can bleeding heart vine 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 bleeding heart vine 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.