Cold hardiness & minimum temperature

Is Red Osier Dogwood (Cornus sericea)cold hardy? Hardiness zone & min temp

Also called red osier dogwood, red-twig dogwood, American dogwood, creek dogwood.

More about red osier dogwood

About Red Osier Dogwood

Cornus sericea · also called red osier dogwood, red-twig dogwood · flowering

Red osier dogwood is a vigorous native North American shrub prized for its brilliant red winter stems and white spring flower clusters. It thrives in moist to wet soils in full sun to part shade, making it ideal for rain gardens and streambanks. Extremely cold-hardy to USDA Zone 2, it provides year-round multi-season interest.

Cold limit: USDA 2-7 · RHS H7 (-40°C to 35°C (-40°F to 95°F))

Watch for — Fading stem colour: Older wood loses its red pigmentation; rejuvenate every 2–3 years by cutting one-third of the oldest stems to the ground in late winter to stimulate bright new growth.

What red osier dogwood's hardiness rating actually means

Yes — red osier dogwood is genuinely cold hardy. Rated RHS H7 and USDA 2-7, 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 2-7 — 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. Red Osier Dogwood is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for red osier dogwood 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 red osier dogwood go outside or overwinter — and where?

Plant it out within USDA 2-7 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 red osier dogwood can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H7 figure above.

Red Osier Dogwood hardiness — frequently asked questions

Is red osier dogwood cold hardy?

Yes — red osier dogwood is genuinely cold hardy. Rated RHS H7 and USDA 2-7, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Red Osier Dogwood is hardy across USDA 2-7; 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 red osier dogwood can survive?

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

What hardiness zone is red osier dogwood?

Red Osier Dogwood is rated USDA 2-7 and RHS H7 — Hardy in the severest European continental winters.

Can red osier dogwood survive winter outside?

Plant it out within USDA 2-7 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 red osier dogwood 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.