Cold hardiness & minimum temperature

Is Salvia nemorosa 'Ostfriesland' (Salvia nemorosa 'Ostfriesland')cold hardy? Hardiness zone & min temp

Also called East Friesland sage, East Friesland salvia.

More about salvia nemorosa 'ostfriesland'

About Salvia nemorosa 'Ostfriesland'

Salvia nemorosa 'Ostfriesland' · also called East Friesland sage, East Friesland salvia · flowering

'Ostfriesland', sold as East Friesland sage, is a tidy, free-flowering hardy perennial with narrow spikes of violet-purple flowers over aromatic grey-green foliage. A reliable, bee-magnet border plant, it wants full sun and sharp drainage, blooms from early summer, and reblooms generously when sheared back after the first flush.

Cold limit: USDA 4-8 · RHS H7 (15-25°C in active growth, hardy to about -20°C dormant)

Watch for — Winter crown rot: Caused by cold, waterlogged soil. Ensure sharp drainage and avoid mulching directly over the crown.

What salvia nemorosa 'ostfriesland''s hardiness rating actually means

Yes — salvia nemorosa 'ostfriesland' is genuinely cold hardy. Rated RHS H7 and USDA 4-8, it lives outdoors all year and needs winter cold rather than protection from it. Its RHS rating of H7 means: Hardy in the severest European continental winters. On the US scale that maps to USDA 4-8 — 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 below about −20 °C. Salvia nemorosa 'Ostfriesland' is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for salvia nemorosa 'ostfriesland' as it gets too cold:

It tolerates winter lows to about −20 °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 salvia nemorosa 'ostfriesland' go outside or overwinter — and where?

Plant it out within USDA 4-8 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 salvia nemorosa 'ostfriesland' can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H7 figure above.

Salvia nemorosa 'Ostfriesland' hardiness — frequently asked questions

Is salvia nemorosa 'ostfriesland' cold hardy?

Yes — salvia nemorosa 'ostfriesland' is genuinely cold hardy. Rated RHS H7 and USDA 4-8, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Salvia nemorosa 'Ostfriesland' is hardy across USDA 4-8; 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 salvia nemorosa 'ostfriesland' can survive?

Minimum survivable temperature is roughly below about −20 °C. Salvia nemorosa 'Ostfriesland' is built for winter — once established it takes hard frost and snow in its stride.

What hardiness zone is salvia nemorosa 'ostfriesland'?

Salvia nemorosa 'Ostfriesland' is rated USDA 4-8 and RHS H7 — Hardy in the severest European continental winters.

Can salvia nemorosa 'ostfriesland' survive winter outside?

Plant it out within USDA 4-8 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 salvia nemorosa 'ostfriesland' below its minimum temperature?

It tolerates winter lows to about −20 °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.