Cold hardiness & minimum temperature

Is Thanksgiving Cactus (Schlumbergera truncata)cold hardy? Hardiness zone & min temp

Also called Crab Cactus, Claw Cactus, Holiday Cactus.

More about thanksgiving cactus

About Thanksgiving Cactus

Schlumbergera truncata · also called Crab Cactus, Claw Cactus · flowering

The Thanksgiving cactus is a Brazilian epiphytic cactus with flattened, toothed green segments — the pointed "claw" margins distinguish it from the rounder Christmas cactus. It blooms in late autumn, its tubular flowers held above the horizontal. Grow it in bright indirect light and chunky, fast-draining mix, watering when the top dries. ASPCA-listed non-toxic.

Cold limit: USDA 10-12 (grown indoors in most US homes) · RHS H1b (18-24°C)

Watch for — Bud drop: Sudden shifts in light, temperature, drafts, or watering during budding make buds abort. Keep conditions stable once buds form and avoid moving the plant.

What thanksgiving cactus's hardiness rating actually means

Thanksgiving Cactus 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 10-12 (grown indoors 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). Thanksgiving Cactus has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

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

Thanksgiving Cactus hardiness — frequently asked questions

Is thanksgiving cactus cold hardy?

Thanksgiving Cactus 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. Thanksgiving Cactus can only live outside year-round in genuinely frost-free climates (roughly USDA 10-12 (grown indoors in most US homes)); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature thanksgiving cactus can survive?

What hardiness zone is thanksgiving cactus?

Thanksgiving Cactus is rated USDA 10-12 (grown indoors 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 thanksgiving cactus 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 thanksgiving cactus 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.