Cold hardiness & minimum temperature

Is Persicaria amplexicaulis 'Alba' (Persicaria amplexicaulis 'Alba')cold hardy? Hardiness zone & min temp

Also called white mountain fleece, white bistort.

More about persicaria amplexicaulis 'alba'

About Persicaria amplexicaulis 'Alba'

Persicaria amplexicaulis 'Alba' · also called white mountain fleece, white bistort · flowering

A robust, long-blooming perennial bearing slender white flower spikes above bold, pointed green leaves from midsummer well into autumn. The white-flowered form of mountain fleece, it forms substantial weed-suppressing clumps up to 1.2 m and thrives in moist borders. Tough, hardy and pollinator-friendly, it anchors naturalistic and prairie-style planting schemes.

Cold limit: USDA 4-8 · RHS H7 (-20 to 28°C)

What persicaria amplexicaulis 'alba''s hardiness rating actually means

Yes — persicaria amplexicaulis 'alba' is genuinely cold hardy. Rated RHS H7 and USDA 4-8, 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 4-8 — 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 below about −20 °C. Persicaria amplexicaulis 'Alba' is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for persicaria amplexicaulis 'alba' 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 persicaria amplexicaulis 'alba' go outside or overwinter — and where?

Plant it out within USDA 4-8 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 persicaria amplexicaulis 'alba' can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H7 figure above.

Persicaria amplexicaulis 'Alba' hardiness — frequently asked questions

Is persicaria amplexicaulis 'alba' cold hardy?

Yes — persicaria amplexicaulis 'alba' is genuinely cold hardy. Rated RHS H7 and USDA 4-8, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Persicaria amplexicaulis 'Alba' is hardy across USDA 4-8; 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 persicaria amplexicaulis 'alba' can survive?

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

What hardiness zone is persicaria amplexicaulis 'alba'?

Persicaria amplexicaulis 'Alba' is rated USDA 4-8 and RHS H7 — Hardy in the severest European continental winters.

Can persicaria amplexicaulis 'alba' survive winter outside?

Plant it out within USDA 4-8 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 persicaria amplexicaulis 'alba' 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.