Cold hardiness & minimum temperature

Is Cape Primrose 'Bristol's Party Girl' (Streptocarpus 'Bristol's Party Girl')cold hardy? Hardiness zone & min temp

Also called Party Girl Cape Primrose.

More about cape primrose 'bristol's party girl'

About Cape Primrose 'Bristol's Party Girl'

Streptocarpus 'Bristol's Party Girl' · also called Party Girl Cape Primrose · flowering

Streptocarpus 'Bristol's Party Girl' is a compact Cape primrose prized for ruffled, pale-pink-and-white flowers veined deeper pink, held on slender stalks above strappy, soft green leaves. An African-violet relative, this stemless gesneriad flowers for much of the year in bright indirect light with cool-to-warm rooms, moderate humidity and careful, root-zone watering.

Cold limit: USDA 10-11 (grown indoors in most US homes) · RHS H1b (16-24°C)

Watch for — Leaf spotting / scorch: Cold water on leaves or direct sun causes pale spots and burnt patches. Keep foliage dry and out of harsh sun.

What cape primrose 'bristol's party girl''s hardiness rating actually means

Cape Primrose 'Bristol's Party Girl' 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 10-11 (grown indoors in most US homes) — 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). Cape Primrose 'Bristol's Party Girl' has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

Concretely, for cape primrose 'bristol's party girl' 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 cape primrose 'bristol's party girl' 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 cape primrose 'bristol's party girl' can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H1b figure above.

Cape Primrose 'Bristol's Party Girl' hardiness — frequently asked questions

Is cape primrose 'bristol's party girl' cold hardy?

Cape Primrose 'Bristol's Party Girl' 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. Cape Primrose 'Bristol's Party Girl' can only live outside year-round in genuinely frost-free climates (roughly USDA 10-11 (grown indoors in most US homes)); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature cape primrose 'bristol's party girl' can survive?

What hardiness zone is cape primrose 'bristol's party girl'?

Cape Primrose 'Bristol's Party Girl' is rated USDA 10-11 (grown indoors in most US homes) and RHS H1b — Sub-tropical — a normal warm home is fine, but it cannot go outside in a cool season.

Can cape primrose 'bristol's party girl' 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 cape primrose 'bristol's party girl' 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.