Cold hardiness & minimum temperature

Is String of Nickels (Dischidia nummularia)cold hardy? Hardiness zone & min temp

Also called String of Coins, String of Buttons, Button Orchid, Coin-leaf Dischidia.

More about string of nickels

About String of Nickels

Dischidia nummularia · also called String of Coins, String of Buttons · houseplant

String of Nickels is an epiphytic trailing plant native to tropical Asia and Australia, prized for its cascading strings of small, round, coin-shaped leaves. It wants bright indirect light, an airy fast-draining epiphytic mix, and high humidity. It is not on the ASPCA list and its milky sap may cause mild stomach upset and skin irritation, so keep it away from curious pets.

Cold limit: USDA 10-12 (16-29°C)

What string of nickels's hardiness rating actually means

String of Nickels 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 — 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 Nickels has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

Concretely, for string of nickels 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 nickels 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 nickels 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 Nickels hardiness — frequently asked questions

Is string of nickels cold hardy?

String of Nickels 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 Nickels can only live outside year-round in genuinely frost-free climates (roughly USDA 10-12); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature string of nickels can survive?

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

What hardiness zone is string of nickels?

String of Nickels is rated USDA 10-12 and RHS H1c — Warm-temperate — can summer outdoors but must come in well before the first frost.

Can string of nickels 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 nickels 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.