Cold hardiness & minimum temperature

Is Bog Bilberry (Vaccinium uliginosum)cold hardy? Hardiness zone & min temp

Also called Bog Bilberry, Bog Blueberry, Alpine Bilberry, Moor Berry.

More about bog bilberry

About Bog Bilberry

Vaccinium uliginosum · also called Bog Bilberry, Bog Blueberry · edible

Vaccinium uliginosum is a deciduous low-growing shrub with a circumpolar distribution across arctic and subarctic tundra, boreal forest margins, and high alpine heathlands of the Northern Hemisphere, including Scotland, Scandinavia, Alaska, Canada, Siberia, and the mountains of central Asia. It produces small urn-shaped pale pink flowers in late spring followed by blue-black berries with a distinctive bloom, edible and nutritious, eaten fresh or cooked. The most important care fact is that it requires acid, moisture-retentive soil but will not tolerate prolonged waterlogging despite being called a 'bog' plant — the name reflects its habitat near wet heath, not fully saturated conditions. Ripe berries are considered edible and are consumed widely; no confirmed ASPCA listing exists and classify as mildly toxic to pets on a precautionary basis.

Cold limit: USDA 2-6 · RHS H7 (-40°C to 25°C)

What bog bilberry's hardiness rating actually means

Yes — bog bilberry 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. Bog Bilberry is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for bog bilberry 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 bog bilberry 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 bog bilberry can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H7 figure above.

Bog Bilberry hardiness — frequently asked questions

Is bog bilberry cold hardy?

Yes — bog bilberry 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. Bog Bilberry 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 bog bilberry can survive?

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

What hardiness zone is bog bilberry?

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

Can bog bilberry 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 bog bilberry 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.