Cold hardiness & minimum temperature

Is Pelargonium triste (Pelargonium triste)cold hardy? Hardiness zone & min temp

Also called Sad geranium, Musky pelargonium, Nightscented pelargonium.

More about pelargonium triste

About Pelargonium triste

Pelargonium triste · also called Sad geranium, Musky pelargonium · houseplant

A tuberous, winter-growing South African pelargonium with finely divided, ferny, carrot-like foliage and dull yellow-and-maroon flowers that release a powerful sweet-musky scent at night. One of the first pelargoniums brought to Europe, it is a connoisseur's geophyte for gritty pots, needing a dry summer dormancy, bright light and frost-free conditions. Slow but long-lived.

Cold limit: USDA 9-11 (tender geophyte; protect from frost, keep above about 5°C) · RHS H1c (10-25°C)

Watch for — Weak, etiolated leaves: Too little light produces floppy, pale foliage. Provide full sun during the winter growing season.

What pelargonium triste's hardiness rating actually means

Pelargonium triste 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 9-11 (tender geophyte; protect from frost, keep above about 5°C) — 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). Pelargonium triste has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

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

Pelargonium triste hardiness — frequently asked questions

Is pelargonium triste cold hardy?

Pelargonium triste 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. Pelargonium triste can only live outside year-round in genuinely frost-free climates (roughly USDA 9-11 (tender geophyte; protect from frost, keep above about 5°C)); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature pelargonium triste can survive?

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

What hardiness zone is pelargonium triste?

Pelargonium triste is rated USDA 9-11 (tender geophyte; protect from frost, keep above about 5°C) and RHS H1c — Warm-temperate — can summer outdoors but must come in well before the first frost.

Can pelargonium triste 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 pelargonium triste 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.