Cold hardiness & minimum temperature

Is Polka Dot Plant 'Splash Select Red' (Hypoestes phyllostachya 'Splash Select Red')cold hardy? Hardiness zone & min temp

Also called red polka dot plant, red freckle face.

More about polka dot plant 'splash select red'

About Polka Dot Plant 'Splash Select Red'

Hypoestes phyllostachya 'Splash Select Red' · also called red polka dot plant, red freckle face · houseplant

'Splash Select Red' is a vivid cultivar of the polka dot plant, its dark green leaves heavily splashed and veined with rosy-pink to red. Compact and bushy, it is grown purely for its freckled foliage. It loves warmth, humidity and bright indirect light, and rewards regular pinching with dense growth, though it sulks dramatically when thirsty.

Cold limit: USDA 10-11 (houseplant or summer bedding elsewhere) · RHS H1b (18-27°C)

What polka dot plant 'splash select red''s hardiness rating actually means

Polka Dot Plant 'Splash Select Red' 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 (houseplant or summer bedding 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 10 °C (sustained cold below this is damaging). Polka Dot Plant 'Splash Select Red' has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

Concretely, for polka dot plant 'splash select red' 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 polka dot plant 'splash select red' 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 polka dot plant 'splash select red' can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H1b figure above.

Polka Dot Plant 'Splash Select Red' hardiness — frequently asked questions

Is polka dot plant 'splash select red' cold hardy?

Polka Dot Plant 'Splash Select Red' 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. Polka Dot Plant 'Splash Select Red' can only live outside year-round in genuinely frost-free climates (roughly USDA 10-11 (houseplant or summer bedding elsewhere)); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature polka dot plant 'splash select red' can survive?

What hardiness zone is polka dot plant 'splash select red'?

Polka Dot Plant 'Splash Select Red' is rated USDA 10-11 (houseplant or summer bedding elsewhere) and RHS H1b — Sub-tropical — a normal warm home is fine, but it cannot go outside in a cool season.

Can polka dot plant 'splash select red' 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 polka dot plant 'splash select red' 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.