Cold hardiness & minimum temperature

Is Common Valerian (Valeriana officinalis)cold hardy? Hardiness zone & min temp

Also called Common Valerian, Garden Valerian, Garden Heliotrope, All-heal.

More about common valerian

About Common Valerian

Valeriana officinalis · also called Common Valerian, Garden Valerian · herb

Valeriana officinalis is a tall, vigorous herbaceous perennial native to Europe and parts of Asia, widely naturalised in North America, and grown historically as a medicinal herb whose roots yield the well-known sedative valerenic acid. It thrives in full sun to partial shade in consistently moist, fertile soil and is commonly found beside streams, in damp meadows, and in cottage gardens. The most important care fact is that it can spread aggressively by self-seeding; deadhead after flowering to keep it contained. Valeriana officinalis is not listed as toxic to cats or dogs by the ASPCA, though it is psychoactive in cats.

Cold limit: USDA 4-9 · RHS H7 (-20 to 28°C)

What common valerian's hardiness rating actually means

Yes — common valerian is genuinely cold hardy. Rated RHS H7 and USDA 4-9, 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 4-9 — 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. Common Valerian is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for common valerian 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 common valerian go outside or overwinter — and where?

Plant it out within USDA 4-9 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 common valerian can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H7 figure above.

Common Valerian hardiness — frequently asked questions

Is common valerian cold hardy?

Yes — common valerian is genuinely cold hardy. Rated RHS H7 and USDA 4-9, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Common Valerian is hardy across USDA 4-9; 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 common valerian can survive?

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

What hardiness zone is common valerian?

Common Valerian is rated USDA 4-9 and RHS H7 — Hardy in the severest European continental winters.

Can common valerian survive winter outside?

Plant it out within USDA 4-9 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 common valerian 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.