Cold hardiness & minimum temperature

Is Graptopetalum pentandrum (Graptopetalum pentandrum)cold hardy? Hardiness zone & min temp

Also called Five-stamened graptopetalum, Ghost plant, Mother of pearl plant, Superbum (subsp. superbum).

More about graptopetalum pentandrum

About Graptopetalum pentandrum

Graptopetalum pentandrum · also called Five-stamened graptopetalum, Ghost plant · houseplant

Graptopetalum pentandrum is a rosette-forming Mexican succulent prized for chalky, farina-dusted lavender-grey leaves. Give it bright full-to-partial sun, gritty well-draining soil, and infrequent soak-and-dry watering. It is drought-tolerant and easy to propagate from leaves or offsets. The ASPCA does not list it, so treat it as unconfirmed and keep it away from pets.

Cold limit: USDA 9b-11b (15-27 C)

What graptopetalum pentandrum's hardiness rating actually means

Graptopetalum pentandrum 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 9b-11b — 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). Graptopetalum pentandrum has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

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

Graptopetalum pentandrum hardiness — frequently asked questions

Is graptopetalum pentandrum cold hardy?

Graptopetalum pentandrum 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. Graptopetalum pentandrum can only live outside year-round in genuinely frost-free climates (roughly USDA 9b-11b); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature graptopetalum pentandrum can survive?

What hardiness zone is graptopetalum pentandrum?

Graptopetalum pentandrum is rated USDA 9b-11b and RHS H1b — Sub-tropical — a normal warm home is fine, but it cannot go outside in a cool season.

Can graptopetalum pentandrum 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 graptopetalum pentandrum 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.