Cold hardiness & minimum temperature

Is Rough Columnea (Columnea strigosa)cold hardy? Hardiness zone & min temp

Also called Rough Columnea, Goldfish Plant.

More about rough columnea

About Rough Columnea

Columnea strigosa · also called Rough Columnea, Goldfish Plant · tropical

Columnea strigosa is a highly variable, epiphytic to terrestrial herbaceous shrub native to the montane rainforests and cloud forests of Colombia, Venezuela, Ecuador, and Peru, where it grows at elevations of 1,500–3,300 m. Its common name 'rough' and the Latin epithet 'strigosa' both refer to the stiff, bristly hairs that cover its stems and leaves. Unusually among commonly cultivated columneas, it features striking dark purple-and-green foliage with bright orange flowers, and its high-altitude origins make it somewhat more tolerant of cool nights than lowland species. Columnea (Gesneriaceae) is non-toxic to cats and dogs per the ASPCA.

Cold limit: USDA 10-12 (indoor in most climates) · RHS H1b (13–22 °C)

Watch for — Crown rot in warm, stagnant conditions: High-altitude origin means C. strigosa is susceptible to fungal crown and stem rot if grown too warm and wet with poor air circulation. Keep temperatures below 24 °C and ensure some air movement around the foliage, especially in an enclosed terrarium.

What rough columnea's hardiness rating actually means

Rough Columnea 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). Rough Columnea has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

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

Rough Columnea hardiness — frequently asked questions

Is rough columnea cold hardy?

Rough Columnea 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. Rough Columnea 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 rough columnea can survive?

What hardiness zone is rough columnea?

Rough Columnea 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 rough columnea 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 rough columnea 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.