Cold hardiness & minimum temperature

Is Swollen-stem Tylecodon (Tylecodon ventricosus)cold hardy? Hardiness zone & min temp

Also called Swollen-stem Tylecodon.

More about swollen-stem tylecodon

About Swollen-stem Tylecodon

Tylecodon ventricosus · also called Swollen-stem Tylecodon · houseplant

A compact South African winter-growing caudex succulent with a visibly swollen, water-storing stem (the 'ventricosus' trait) bearing small deciduous leaves in the cool season. Flowers in late winter to early spring with pink to white blooms. Distinctly winter-active and summer dormant. Requires completely dry rest in summer and bright, airy conditions year-round.

Cold limit: USDA 10–11 · RHS H1c (5–30°C)

What swollen-stem tylecodon's hardiness rating actually means

Swollen-stem Tylecodon 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 — 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). Swollen-stem Tylecodon has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

Concretely, for swollen-stem tylecodon 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 swollen-stem tylecodon 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 swollen-stem tylecodon can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H1c figure above.

Swollen-stem Tylecodon hardiness — frequently asked questions

Is swollen-stem tylecodon cold hardy?

Swollen-stem Tylecodon 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. Swollen-stem Tylecodon can only live outside year-round in genuinely frost-free climates (roughly USDA 10–11); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature swollen-stem tylecodon can survive?

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

What hardiness zone is swollen-stem tylecodon?

Swollen-stem Tylecodon is rated USDA 10–11 and RHS H1c — Warm-temperate — can summer outdoors but must come in well before the first frost.

Can swollen-stem tylecodon 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 swollen-stem tylecodon 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.