Cold hardiness & minimum temperature

Is Purple Sage (Salvia officinalis 'Purpurascens')cold hardy? Hardiness zone & min temp

Also called Red Sage.

More about purple sage

About Purple Sage

Salvia officinalis 'Purpurascens' · also called Red Sage · herb

Purple sage is a culinary cultivar of common sage with soft, aromatic, purple-flushed young foliage that matures to dusky grey-purple. A hardy evergreen sub-shrub, it is used like ordinary sage in cooking and thrives in full sun and sharp drainage. It dislikes wet, heavy soil and grows woody with age without pruning.

Cold limit: USDA 5-9 (hardy evergreen sub-shrub) · RHS H5 (-12 to 30°C)

Watch for — Root rot: Wet, heavy soil rots the roots and is the main cause of death; plant in gritty, free-draining soil and avoid winter waterlogging.

What purple sage's hardiness rating actually means

Yes — purple sage is genuinely cold hardy. Rated RHS H5 and USDA 5-9 (hardy evergreen sub-shrub), it lives outdoors all year and needs winter cold rather than protection from it. Its RHS rating of H5 means: Hardy in most of the UK and in cold winters. On the US scale that maps to USDA 5-9 (hardy evergreen sub-shrub) — 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 −15 to −10 °C. Purple Sage is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for purple sage as it gets too cold:

It tolerates winter lows to about −15 to −10 °C once established.
Below its rated zone, the visible damage is browned or blackened top growth and, in the worst case, a killed crown or root.
First-year, newly planted, or container-grown specimens are noticeably less hardy than established garden plants — the roots are exposed.

Can purple sage go outside or overwinter — and where?

Plant it out within USDA 5-9 (hardy evergreen sub-shrub) and it overwinters with little or no help.
It does not want to come indoors — a warm winter room actually weakens a hardy plant by denying it dormancy.
The real risks in its range are waterlogging, wind-rock on young plants, and a late hard frost on new growth — not ordinary winter cold.

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 purple sage can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H5 figure above.

Purple Sage hardiness — frequently asked questions

Is purple sage cold hardy?

Yes — purple sage is genuinely cold hardy. Rated RHS H5 and USDA 5-9 (hardy evergreen sub-shrub), it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Purple Sage is hardy across USDA 5-9 (hardy evergreen sub-shrub); it belongs in the ground or a frost-proof container, not on a windowsill, and many types actively need a cold winter to perform.

What is the minimum temperature purple sage can survive?

Minimum survivable temperature is roughly about −15 to −10 °C. Purple Sage is built for winter — once established it takes hard frost and snow in its stride.

What hardiness zone is purple sage?

Purple Sage is rated USDA 5-9 (hardy evergreen sub-shrub) and RHS H5 — Hardy in most of the UK and in cold winters.

Can purple sage survive winter outside?

Plant it out within USDA 5-9 (hardy evergreen sub-shrub) and it overwinters with little or no help. It does not want to come indoors — a warm winter room actually weakens a hardy plant by denying it dormancy. The real risks in its range are waterlogging, wind-rock on young plants, and a late hard frost on new growth — not ordinary winter cold.

What happens to purple sage below its minimum temperature?

It tolerates winter lows to about −15 to −10 °C once established. Below its rated zone, the visible damage is browned or blackened top growth and, in the worst case, a killed crown or root. First-year, newly planted, or container-grown specimens are noticeably less hardy than established garden plants — the roots are exposed.