Cold hardiness & minimum temperature

Is Mountain Desert Sage (Salvia pachyphylla)cold hardy? Hardiness zone & min temp

Also called Mountain desert sage, Rose sage, Mojave sage, Thick-leaved sage.

More about mountain desert sage

About Mountain Desert Sage

Salvia pachyphylla · also called Mountain desert sage, Rose sage · flowering

Salvia pachyphylla is a silvery, intensely aromatic sub-shrub native to the mountains and high desert of the Mojave and Sonoran regions of southern California and Baja California, typically growing at elevations of 1,500–3,000 m. It produces long-lasting, showy spikes of violet-blue flowers emerging from persistent dusty-rose to mauve bracts from late June through to September. The most critical care fact is that it demands excellent drainage and full sun, and will decline or die in heavy, moist soil particularly in winter — it is built for dry, rocky habitats. According to the ASPCA, sage (Salvia spp.) is listed as non-toxic to cats, dogs, and horses.

Cold limit: USDA 5-10 · RHS H5 (-20 to 40°C)

Watch for — Crown and root rot in wet soils: The single greatest threat; poorly drained or clay soils, or excessive irrigation in winter, cause rapid crown and root rot — sharp drainage and a dry winter rest are essential.

What mountain desert sage's hardiness rating actually means

Yes — mountain desert sage is genuinely cold hardy. Rated RHS H5 and USDA 5-10, 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 5-10 — 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. Mountain Desert Sage is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for mountain desert 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 mountain desert sage go outside or overwinter — and where?

Plant it out within USDA 5-10 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 mountain desert sage can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H5 figure above.

Mountain Desert Sage hardiness — frequently asked questions

Is mountain desert sage cold hardy?

Yes — mountain desert sage is genuinely cold hardy. Rated RHS H5 and USDA 5-10, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Mountain Desert Sage is hardy across USDA 5-10; 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 mountain desert sage can survive?

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

What hardiness zone is mountain desert sage?

Mountain Desert Sage is rated USDA 5-10 and RHS H5 — Hardy in most of the UK and in cold winters.

Can mountain desert sage survive winter outside?

Plant it out within USDA 5-10 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 mountain desert 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.