Cold hardiness & minimum temperature

Is Guatemalan Blue Sage (Salvia cacaliifolia)cold hardy? Hardiness zone & min temp

Also called Guatemalan Blue Sage, Guatemalan Leaf Sage, Blue Vine Sage, Cacalia Sage.

More about guatemalan blue sage

About Guatemalan Blue Sage

Salvia cacaliifolia · also called Guatemalan Blue Sage, Guatemalan Leaf Sage · flowering

Salvia cacaliifolia is an elegant, erect herbaceous perennial from the highlands of southern Mexico and Guatemala, grown for its striking gentian-blue flowers held in tall arching panicles from midsummer to late autumn. Its triangular, ivy-like leaves add textural interest and the plant performs best with a degree of shade, making it useful for dappled woodland garden conditions. It holds the RHS Award of Garden Merit but is frost-tender and must be overwintered under glass in the UK. The ASPCA considers Salvia (sage) non-toxic to dogs and cats.

Cold limit: USDA 8-11 · RHS H2 (5–30°C (frost-free minimum))

What guatemalan blue sage's hardiness rating actually means

Guatemalan Blue 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 8-11 — 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. Guatemalan Blue Sage shrugs off cold nights but a real, sustained freeze will kill it.

Concretely, for guatemalan blue 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 guatemalan blue sage go outside or overwinter — and where?

It can live outside year-round only in the mildest, most sheltered part of USDA 8-11 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 guatemalan blue 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 guatemalan blue sage

Guatemalan Blue 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.

Guatemalan Blue Sage hardiness — frequently asked questions

Is guatemalan blue sage cold hardy?

Guatemalan Blue 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 8-11 (and sheltered UK gardens) guatemalan blue 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 guatemalan blue sage can survive?

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

What hardiness zone is guatemalan blue sage?

Guatemalan Blue Sage is rated USDA 8-11 and RHS H2 — Tender — survives a frost-free greenhouse or a very mild, sheltered spot.

Can guatemalan blue sage survive winter outside?

It can live outside year-round only in the mildest, most sheltered part of USDA 8-11 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 guatemalan blue 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.