Cold hardiness & minimum temperature

Is Schwantes' Living Stone (Lithops schwantesii)cold hardy? Hardiness zone & min temp

Also called Schwantes' Mimicry Plant, Yellow Living Stone, Pebble Plant.

More about schwantes' living stone

About Schwantes' Living Stone

Lithops schwantesii · also called Schwantes' Mimicry Plant, Yellow Living Stone · houseplant

Lithops schwantesii is a widely cultivated South African stone-plant bearing grey-yellow to brownish lobes with distinctive rugged surface texturing and channel markings. It is one of the more vigorous Lithops species and produces bright yellow flowers in autumn. Non-toxic to pets. Its relative vigour makes it a good species for beginners provided the seasonal watering rules are respected.

Cold limit: USDA 10-11 (indoor-only in most climates) · RHS H1c (10-30°C)

Watch for — Old lobe pair not shrivelling: A sign of excess moisture in the mid-winter rest period. Stop watering immediately and wait for natural desiccation.

What schwantes' living stone's hardiness rating actually means

Schwantes' Living Stone 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 H1c means: Warm-temperate — can summer outdoors but must come in well before the first frost. On the US scale that maps to USDA 10-11 (indoor-only 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 5 °C (and never frost). Schwantes' Living Stone has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

Concretely, for schwantes' living stone as it gets too cold:

Below about about 5 °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 schwantes' living stone go outside or overwinter — and where?

It can holiday outdoors in summer once nights are reliably above 5 °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 schwantes' living stone can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H1c figure above.

Schwantes' Living Stone hardiness — frequently asked questions

Is schwantes' living stone cold hardy?

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

What is the minimum temperature schwantes' living stone can survive?

Minimum survivable temperature is roughly about 5 °C (and never frost). Schwantes' Living Stone has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

What hardiness zone is schwantes' living stone?

Schwantes' Living Stone is rated USDA 10-11 (indoor-only in most climates) and RHS H1c — Warm-temperate — can summer outdoors but must come in well before the first frost.

Can schwantes' living stone survive winter outside?

It can holiday outdoors in summer once nights are reliably above 5 °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 schwantes' living stone below its minimum temperature?

Below about about 5 °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.