Cold hardiness & minimum temperature

Is Sinningia 'Duchess of York' (Sinningia 'Duchess of York')cold hardy? Hardiness zone & min temp

Also called Duchess of York gloxinia.

More about sinningia 'duchess of york'

About Sinningia 'Duchess of York'

Sinningia 'Duchess of York' · also called Duchess of York gloxinia · flowering

Sinningia 'Duchess of York' is a hybrid florist gloxinia grown for huge, double, ruffled bell flowers in red edged with white. The velvety, tuberous gesneriad blooms over weeks indoors, then dies back to its tuber for a winter dormancy. Give it bright indirect light, even moisture, and warmth to coax repeat flushes.

Cold limit: USDA 11-12 (grown as an indoor pot plant in most US homes) · RHS H1b (18-24°C)

Watch for — Leaf ring-spot and rot: Cold water or droplets sitting on the velvety leaves cause pale rings or rotting patches. Water from below with tepid water and keep foliage dry.

What sinningia 'duchess of york''s hardiness rating actually means

Sinningia 'Duchess of York' 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 11-12 (grown as an indoor pot plant 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). Sinningia 'Duchess of York' has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

Concretely, for sinningia 'duchess of york' 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 sinningia 'duchess of york' 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 sinningia 'duchess of york' can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H1b figure above.

Sinningia 'Duchess of York' hardiness — frequently asked questions

Is sinningia 'duchess of york' cold hardy?

Sinningia 'Duchess of York' 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. Sinningia 'Duchess of York' can only live outside year-round in genuinely frost-free climates (roughly USDA 11-12 (grown as an indoor pot plant in most US homes)); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature sinningia 'duchess of york' can survive?

What hardiness zone is sinningia 'duchess of york'?

Sinningia 'Duchess of York' is rated USDA 11-12 (grown as an indoor pot plant 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 sinningia 'duchess of york' 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 sinningia 'duchess of york' 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.