Cold hardiness & minimum temperature

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

Also called string of tears, string of watermelons, gooseberry plant.

More about string of tears

About String of Tears

Curio herreianus · also called string of tears, string of watermelons · houseplant

String of tears is a trailing succulent (formerly Senecio herreianus) whose plump, tear- or watermelon-shaped beads are striped with darker translucent lines that act as light windows. Closely related to string of pearls, it wants bright light, very sparing water, and gritty soil. It cascades attractively from a hanging pot but resents wet feet.

Cold limit: USDA 10-12 (indoor in most US homes) · RHS H1c (18-27°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 10-12 (indoor 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 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 10-12 (indoor in most US homes)); 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 10-12 (indoor in most US homes) 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.