Cold hardiness & minimum temperature

Is String of Tears (Curio herreanus)cold hardy? Hardiness zone & min temp

Also called String of tears, String of beads, String of watermelons, String of raindrops, Gooseberry plant.

More about string of tears

About String of Tears

Curio herreanus · also called String of tears, String of beads · houseplant

String of tears (Curio herreanus, formerly Senecio herreianus) is a Namibian trailing succulent prized for cascading stems of plump, tear-shaped beads with faint purple stripes. Give it bright indirect light, a gritty cactus mix, and infrequent soak-and-dry watering. Treat it as mildly toxic to pets; the ASPCA flags its close relative, string of pearls.

Cold limit: USDA USDA zone 10 (frost-tender; some sources list 9-11). Grow as an indoor or container plant outside zones 10-11 and protect from frost. (15-29 C)

What string of tears's hardiness rating actually means

String of Tears 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 USDA zone 10 (frost-tender; some sources list 9-11). Grow as an indoor or container plant outside zones 10-11 and protect from frost. — 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). String of Tears has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

Concretely, for string of tears 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 string of tears 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 string of tears can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H1c figure above.

String of Tears hardiness — frequently asked questions

Is string of tears cold hardy?

String of Tears 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. String of Tears can only live outside year-round in genuinely frost-free climates (roughly USDA USDA zone 10 (frost-tender; some sources list 9-11). Grow as an indoor or container plant outside zones 10-11 and protect from frost.); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature string of tears can survive?

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

What hardiness zone is string of tears?

String of Tears is rated USDA USDA zone 10 (frost-tender; some sources list 9-11). Grow as an indoor or container plant outside zones 10-11 and protect from frost. and RHS H1c — Warm-temperate — can summer outdoors but must come in well before the first frost.

Can string of tears 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 string of tears 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.