Cold hardiness & minimum temperature

Is Siberian Bugloss 'Hadspen Cream' (Brunnera macrophylla)cold hardy? Hardiness zone & min temp

Also called Hadspen Cream Siberian Bugloss, False Forget-Me-Not, Great Forget-Me-Not.

More about siberian bugloss 'hadspen cream'

About Siberian Bugloss 'Hadspen Cream'

Brunnera macrophylla · also called Hadspen Cream Siberian Bugloss, False Forget-Me-Not · flowering

Siberian Bugloss 'Hadspen Cream' is a clump-forming shade perennial with large, heart-shaped leaves edged in irregular creamy-white, and delicate sky-blue forget-me-not flowers in spring. A superb ground cover for shaded borders. Prefers cool, moist conditions. Not considered toxic to pets.

Cold limit: USDA 3-8 · RHS H6 (-20-22°C)

What siberian bugloss 'hadspen cream''s hardiness rating actually means

Yes — siberian bugloss 'hadspen cream' is genuinely cold hardy. Rated RHS H6 and USDA 3-8, it lives outdoors all year and needs winter cold rather than protection from it. Its RHS rating of H6 means: Hardy throughout the UK and northern Europe. On the US scale that maps to USDA 3-8 — 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 about −20 to −15 °C. Siberian Bugloss 'Hadspen Cream' is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for siberian bugloss 'hadspen cream' as it gets too cold:

It tolerates winter lows to about −20 to −15 °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 siberian bugloss 'hadspen cream' go outside or overwinter — and where?

Plant it out within USDA 3-8 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 siberian bugloss 'hadspen cream' can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H6 figure above.

Siberian Bugloss 'Hadspen Cream' hardiness — frequently asked questions

Is siberian bugloss 'hadspen cream' cold hardy?

Yes — siberian bugloss 'hadspen cream' is genuinely cold hardy. Rated RHS H6 and USDA 3-8, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Siberian Bugloss 'Hadspen Cream' is hardy across USDA 3-8; 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 siberian bugloss 'hadspen cream' can survive?

Minimum survivable temperature is roughly about −20 to −15 °C. Siberian Bugloss 'Hadspen Cream' is built for winter — once established it takes hard frost and snow in its stride.

What hardiness zone is siberian bugloss 'hadspen cream'?

Siberian Bugloss 'Hadspen Cream' is rated USDA 3-8 and RHS H6 — Hardy throughout the UK and northern Europe.

Can siberian bugloss 'hadspen cream' survive winter outside?

Plant it out within USDA 3-8 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 siberian bugloss 'hadspen cream' below its minimum temperature?

It tolerates winter lows to about −20 to −15 °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.