Cold hardiness & minimum temperature

Is Grey Saltbush (Atriplex cinerea)cold hardy? Hardiness zone & min temp

Also called Grey saltbush, Coast saltbush, Barilla.

More about grey saltbush

About Grey Saltbush

Atriplex cinerea · also called Grey saltbush, Coast saltbush · edible

Atriplex cinerea is an evergreen, silver-grey shrub endemic to coastal regions and salt lake margins of southern Australia (Western Australia, South Australia, Victoria, Tasmania, and New South Wales). It thrives in full sun on saline, sandy or loamy coastal soils and is frost-tender, making it suitable for mild-winter gardens or sheltered coastal positions in the UK. The salt-rich leaves are edible and have a history as a bush-tucker food and bioremediation plant. Not known to be toxic to cats or dogs.

Cold limit: USDA 9-11 · RHS H2 (0°C to 40°C)

Watch for — Frost damage: Frost-tender; prolonged temperatures below 0°C will kill stems back to the base or kill the plant entirely — grow against a sheltered south- or west-facing wall in frost-prone areas, or overwinter cuttings under glass.

What grey saltbush's hardiness rating actually means

Grey Saltbush 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. Grey Saltbush shrugs off cold nights but a real, sustained freeze will kill it.

Concretely, for grey saltbush 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 grey saltbush 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 grey saltbush 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 grey saltbush

Grey Saltbush 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.

Grey Saltbush hardiness — frequently asked questions

Is grey saltbush cold hardy?

Grey Saltbush 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) grey saltbush can stay out; in colder areas it must be lifted, brought in, or treated as a frost-tender plant.

What is the minimum temperature grey saltbush can survive?

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

What hardiness zone is grey saltbush?

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

Can grey saltbush 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 grey saltbush 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.