Cold hardiness & minimum temperature

Is Wavy-margin Primulina (Primulina repanda)cold hardy? Hardiness zone & min temp

Also called Wavy-margin Primulina, Wavy-leaf Primulina, Repand Primulina.

More about wavy-margin primulina

About Wavy-margin Primulina

Primulina repanda · also called Wavy-margin Primulina, Wavy-leaf Primulina · houseplant

Primulina repanda is a gesneriad from humid limestone gorges and cliff shelters in southern China, recognisable by its characteristically wavy or undulating leaf margins that give it both its common and Latin name. Like all Primulina, it demands bright filtered light, high humidity, and fast-draining compost — conditions that replicate the damp but never waterlogged limestone habitats of Guangxi province. Avoid wetting the scalloped leaf surface when watering, as trapped moisture in the ridges promotes fungal leaf spot. Not listed by the ASPCA; treat as mildly toxic and keep away from cats and dogs.

Cold limit: USDA 10-12 (indoor in most climates) · RHS H1b (14–25°C)

What wavy-margin primulina's hardiness rating actually means

Wavy-margin Primulina 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 10-12 (indoor in most climates) — 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). Wavy-margin Primulina has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

Concretely, for wavy-margin primulina 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 wavy-margin primulina 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 wavy-margin primulina can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H1b figure above.

Wavy-margin Primulina hardiness — frequently asked questions

Is wavy-margin primulina cold hardy?

Wavy-margin Primulina 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. Wavy-margin Primulina can only live outside year-round in genuinely frost-free climates (roughly USDA 10-12 (indoor in most climates)); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature wavy-margin primulina can survive?

What hardiness zone is wavy-margin primulina?

Wavy-margin Primulina is rated USDA 10-12 (indoor in most climates) and RHS H1b — Sub-tropical — a normal warm home is fine, but it cannot go outside in a cool season.

Can wavy-margin primulina 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 wavy-margin primulina 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.