Cold hardiness & minimum temperature

Is Crowberry (Empetrum nigrum)cold hardy? Hardiness zone & min temp

Also called Crowberry, Black Crowberry, Mossberry, Curlew Berry.

More about crowberry

About Crowberry

Empetrum nigrum · also called Crowberry, Black Crowberry · edible

Empetrum nigrum is a low-growing, mat-forming evergreen shrub native to Arctic and sub-Arctic regions, moorlands, and high-altitude bogs across the Northern Hemisphere. It thrives in full sun on acidic, nutrient-poor, peaty or sandy soils with excellent drainage, and is exceptionally frost-hardy. The most important care fact is that it strongly resents fertiliser — any added nitrogen encourages soft, susceptible growth and disrupts its adaptation to infertile substrates. The berries are edible and widely used in Scandinavian and Indigenous Northern cuisine; the plant is considered non-toxic to pets.

Cold limit: USDA 2-6 · RHS H7 (-40°C to 20°C)

What crowberry's hardiness rating actually means

Yes — crowberry is genuinely cold hardy. Rated RHS H7 and USDA 2-6, 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 2-6 — 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. Crowberry is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for crowberry 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 crowberry go outside or overwinter — and where?

Plant it out within USDA 2-6 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 crowberry can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H7 figure above.

Crowberry hardiness — frequently asked questions

Is crowberry cold hardy?

Yes — crowberry is genuinely cold hardy. Rated RHS H7 and USDA 2-6, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Crowberry is hardy across USDA 2-6; 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 crowberry can survive?

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

What hardiness zone is crowberry?

Crowberry is rated USDA 2-6 and RHS H7 — Hardy in the severest European continental winters.

Can crowberry survive winter outside?

Plant it out within USDA 2-6 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 crowberry 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.