Cold hardiness & minimum temperature

Is Common Bistort (Persicaria bistorta)cold hardy? Hardiness zone & min temp

Also called Common Bistort, Meadow Bistort, Snakeweed, Patience Dock.

More about common bistort

About Common Bistort

Persicaria bistorta · also called Common Bistort, Meadow Bistort · flowering

Persicaria bistorta is a rhizomatous perennial native to Europe and western Asia, commonly found in damp meadows, stream banks, and boggy ground. It thrives in moist to wet, moderately fertile soils in full sun to partial shade, producing dense spikes of soft-pink flowers from late spring into summer. The single most important care fact is consistent soil moisture — it will not tolerate drought and performs best at pond or stream edges. Persicaria bistorta is not listed on the ASPCA toxic-plant database; it contains oxalic acid so large quantities should be avoided by pets and humans, making it mildly-toxic by caution.

Cold limit: USDA 4-8 · RHS H7 (-30 to 25°C)

What common bistort's hardiness rating actually means

Yes — common bistort 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. Common Bistort is built for winter — once established it takes hard frost and snow in its stride.

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

Common Bistort hardiness — frequently asked questions

Is common bistort cold hardy?

Yes — common bistort 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. Common Bistort 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 common bistort can survive?

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

What hardiness zone is common bistort?

Common Bistort is rated USDA 4-8 and RHS H7 — Hardy in the severest European continental winters.

Can common bistort 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 common bistort 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.