Cold hardiness & minimum temperature

Is Alsobia 'San Miguel' (Alsobia 'San Miguel')cold hardy? Hardiness zone & min temp

Also called San Miguel alsobia, San Miguel lace flower.

More about alsobia 'san miguel'

About Alsobia 'San Miguel'

Alsobia 'San Miguel' · also called San Miguel alsobia, San Miguel lace flower · flowering

Alsobia 'San Miguel' is a stoloniferous gesneriad grown for fringed white lace flowers over soft, quilted green foliage. A trailing African-violet relative, it spreads on runners like a strawberry and thrives in warm, humid, brightly diffused conditions. Ideal for hanging baskets or terrariums, it stays compact and flowers freely when light and moisture are steady.

Cold limit: USDA 10-11 (indoor in most US homes) · RHS H1b (18-27°C)

Watch for — Leaf spotting: Cold water or water sitting on the fuzzy leaves causes pale blotches. Water at the soil line with tepid water and avoid wetting the foliage.

What alsobia 'san miguel''s hardiness rating actually means

Alsobia 'San Miguel' 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 (indoor 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). Alsobia 'San Miguel' has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

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

Alsobia 'San Miguel' hardiness — frequently asked questions

Is alsobia 'san miguel' cold hardy?

Alsobia 'San Miguel' 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. Alsobia 'San Miguel' can only live outside year-round in genuinely frost-free climates (roughly USDA 10-11 (indoor in most US homes)); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature alsobia 'san miguel' can survive?

What hardiness zone is alsobia 'san miguel'?

Alsobia 'San Miguel' is rated USDA 10-11 (indoor 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 alsobia 'san miguel' 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 alsobia 'san miguel' 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.