Cold hardiness & minimum temperature

Is Salvia (Salvia splendens)cold hardy? Hardiness zone & min temp

Also called scarlet sage, red salvia, tropical sage.

About Salvia

Salvia splendens · also called scarlet sage, red salvia · flowering

Salvia splendens is a tender perennial Brazilian sage grown as an annual for fire-engine red flower spikes that attract hummingbirds. Other Salvia species are hardier and equally pollinator-friendly. Pet-safe.

Salvia is the largest genus in the mint family (roughly 900 species) spanning annuals, biennials, perennials and shrubs, with garden types mainly from the Mediterranean and the Americas.

An RHS Plants for Pollinators group: tubular-flowered species are major nectar sources, with hummingbird pollination documented in 184 New World species and bees favoring the herb sages.

Cold limit: USDA 10-11 (annual elsewhere); other Salvia hardier · RHS H1c (S. splendens); higher for perennial Salvia (15-26°C)

Watch for — Frost damage: Bring indoors as a houseplant or treat as annual.

Sources: extension.umn.edu, rhs.org.uk, hort.extension.wisc.edu

What salvia's hardiness rating actually means

Salvia 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 (annual elsewhere); other Salvia hardier — 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). Salvia has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

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

Salvia hardiness — frequently asked questions

Is salvia cold hardy?

Salvia 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. Salvia can only live outside year-round in genuinely frost-free climates (roughly USDA 10-11 (annual elsewhere); other Salvia hardier); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature salvia can survive?

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

What hardiness zone is salvia?

Salvia is rated USDA 10-11 (annual elsewhere); other Salvia hardier and RHS H1c — Warm-temperate — can summer outdoors but must come in well before the first frost.

Can salvia 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 salvia 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.