Cold hardiness & minimum temperature

Is Opposite-Flowered Sage (Salvia oppositiflora)cold hardy? Hardiness zone & min temp

Also called Opposite-flowered sage, Peruvian salmon sage.

More about opposite-flowered sage

About Opposite-Flowered Sage

Salvia oppositiflora · also called Opposite-flowered sage, Peruvian salmon sage · tropical

Salvia oppositiflora is a tender herbaceous perennial native to the high-altitude regions of Peru (7,000–12,000 ft), producing striking pairs of orange-red, tubular flowers from which it takes its botanical name. In frost-prone climates it is treated as a half-hardy annual or overwintered under cover, as it tolerates no frost. It demands bright sun and well-drained soil; the most important care point is to provide frost protection from late autumn through spring in any climate below USDA Zone 9. The ASPCA does not specifically list Salvia oppositiflora; as a precaution it is classified here as mildly-toxic pending verified ASPCA confirmation.

Cold limit: USDA 9-11 · RHS H2 (5 to 30°C)

Watch for — Frost damage: Any frost will blacken stems and kill the plant; bring indoors or take cuttings before the first autumn frost, and do not plant out until all frost risk has passed in spring.

What opposite-flowered sage's hardiness rating actually means

Opposite-Flowered Sage is half-hardy (RHS H2). It survives a mild winter outdoors in a sheltered spot, but a hard frost kills it — so in colder zones it is lifted, potted, or grown as a tender plant. Its RHS rating of H2 means: Tender — survives a frost-free greenhouse or a very mild, sheltered spot. On the US scale that maps to USDA 9-11 — 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 1 to 5 °C — tolerates cold but no real frost. Opposite-Flowered Sage shrugs off cold nights but a real, sustained freeze will kill it.

Concretely, for opposite-flowered sage as it gets too cold:

Down to roughly about 1 to 5 °C it copes, especially if dry and sheltered.
A sustained hard frost collapses the top growth; whether it returns depends on whether the roots, crown or tubers froze.
Wet cold is far more lethal than dry cold for this plant — soggy, frozen soil is the usual killer.

Can opposite-flowered sage go outside or overwinter — and where?

It can live outside year-round only in the mildest, most sheltered part of USDA 9-11 or a frost-free UK microclimate.
In colder zones, grow it in a pot you can move under cover, or lift its tubers/roots and store them frost-free over winter.
A south-facing wall, free-draining soil and a dry winter position can push it a full zone hardier than the books suggest.

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 opposite-flowered sage can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H2 figure above.

Frost protection for borderline opposite-flowered sage

Opposite-Flowered Sage is right on a hardiness edge in many gardens, so if you are pushing it, these measures buy it the margin it needs:

Mulch the crown or root zone deeply with bark, straw or leaf-mould before the first hard frost.
Move container plants against a warm wall or into an unheated but frost-free porch or greenhouse.
Fleece the top growth on the coldest nights, and keep it on the dry side — dry roots survive cold far better than wet ones.
Lift dahlia-type tubers or tender crowns after the first light frost blackens the foliage and store them somewhere cool but frost-free.

Opposite-Flowered Sage hardiness — frequently asked questions

Is opposite-flowered sage cold hardy?

Opposite-Flowered Sage is half-hardy (RHS H2). It survives a mild winter outdoors in a sheltered spot, but a hard frost kills it — so in colder zones it is lifted, potted, or grown as a tender plant. Borderline outdoors. In its mild end of USDA 9-11 (and sheltered UK gardens) opposite-flowered sage can stay out; in colder areas it must be lifted, brought in, or treated as a frost-tender plant.

What is the minimum temperature opposite-flowered sage can survive?

Minimum survivable temperature is roughly about 1 to 5 °C — tolerates cold but no real frost. Opposite-Flowered Sage shrugs off cold nights but a real, sustained freeze will kill it.

What hardiness zone is opposite-flowered sage?

Opposite-Flowered Sage is rated USDA 9-11 and RHS H2 — Tender — survives a frost-free greenhouse or a very mild, sheltered spot.

Can opposite-flowered sage survive winter outside?

It can live outside year-round only in the mildest, most sheltered part of USDA 9-11 or a frost-free UK microclimate. In colder zones, grow it in a pot you can move under cover, or lift its tubers/roots and store them frost-free over winter. A south-facing wall, free-draining soil and a dry winter position can push it a full zone hardier than the books suggest.

How do I protect opposite-flowered sage from frost?

Mulch the crown or root zone deeply with bark, straw or leaf-mould before the first hard frost. Move container plants against a warm wall or into an unheated but frost-free porch or greenhouse. Fleece the top growth on the coldest nights, and keep it on the dry side — dry roots survive cold far better than wet ones. Lift dahlia-type tubers or tender crowns after the first light frost blackens the foliage and store them somewhere cool but frost-free.