Cold hardiness & minimum temperature

Is Schlumbergera × buckleyi (Schlumbergera × buckleyi)cold hardy? Hardiness zone & min temp

Also called Christmas cactus, holiday cactus.

More about schlumbergera × buckleyi

About Schlumbergera × buckleyi

Schlumbergera × buckleyi · also called Christmas cactus, holiday cactus · flowering

Schlumbergera × buckleyi is the true Christmas cactus, an epiphytic Brazilian forest cactus with flattened, scalloped segmented stems and arching, tubular pink-to-magenta flowers in early winter. Unlike desert cacti it wants humidity, even moisture and bright indirect light. Reliable winter bloom depends on cool nights and long autumn darkness to set buds. Long-lived and easy from cuttings.

Cold limit: USDA 10-12 (indoor in most US and UK homes; frost-tender) · RHS H1b (16-24°C)

Watch for — Bud drop: Triggered by being moved, by draughts, temperature swings, or letting the soil dry out while in bud. Keep conditions stable and watering even once buds form.

What schlumbergera × buckleyi's hardiness rating actually means

Schlumbergera × buckleyi 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 (indoor in most US and UK homes; frost-tender) — 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). Schlumbergera × buckleyi has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

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

Schlumbergera × buckleyi hardiness — frequently asked questions

Is schlumbergera × buckleyi cold hardy?

Schlumbergera × buckleyi 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. Schlumbergera × buckleyi can only live outside year-round in genuinely frost-free climates (roughly USDA 10-12 (indoor in most US and UK homes; frost-tender)); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature schlumbergera × buckleyi can survive?

What hardiness zone is schlumbergera × buckleyi?

Schlumbergera × buckleyi is rated USDA 10-12 (indoor in most US and UK homes; frost-tender) and RHS H1b — Sub-tropical — a normal warm home is fine, but it cannot go outside in a cool season.

Can schlumbergera × buckleyi 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 schlumbergera × buckleyi 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.