Cold hardiness & minimum temperature

Is Sagittaria latifolia (Sagittaria latifolia)cold hardy? Hardiness zone & min temp

Also called Broadleaf Arrowhead, Duck Potato, Wapato.

More about sagittaria latifolia

About Sagittaria latifolia

Sagittaria latifolia · also called Broadleaf Arrowhead, Duck Potato · flowering

A North American native marginal with bold arrow-shaped leaves and whorls of three-petalled white flowers in summer, growing in shallow pond edges and marshes in full sun. It spreads by rhizomes and produces edible starchy tubers (wapato) long used by Native peoples. Not ASPCA-listed; raw plant is acrid, so treat with caution around pets.

Cold limit: USDA 4-10 · RHS H5 (-29 to 32°C)

What sagittaria latifolia's hardiness rating actually means

Yes — sagittaria latifolia is genuinely cold hardy. Rated RHS H5 and USDA 4-10, it lives outdoors all year and needs winter cold rather than protection from it. Its RHS rating of H5 means: Hardy in most of the UK and in cold winters. On the US scale that maps to USDA 4-10 — 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 −15 to −10 °C. Sagittaria latifolia is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for sagittaria latifolia as it gets too cold:

It tolerates winter lows to about −15 to −10 °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 sagittaria latifolia go outside or overwinter — and where?

Plant it out within USDA 4-10 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 sagittaria latifolia can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H5 figure above.

Sagittaria latifolia hardiness — frequently asked questions

Is sagittaria latifolia cold hardy?

Yes — sagittaria latifolia is genuinely cold hardy. Rated RHS H5 and USDA 4-10, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Sagittaria latifolia is hardy across USDA 4-10; 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 sagittaria latifolia can survive?

Minimum survivable temperature is roughly about −15 to −10 °C. Sagittaria latifolia is built for winter — once established it takes hard frost and snow in its stride.

What hardiness zone is sagittaria latifolia?

Sagittaria latifolia is rated USDA 4-10 and RHS H5 — Hardy in most of the UK and in cold winters.

Can sagittaria latifolia survive winter outside?

Plant it out within USDA 4-10 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 sagittaria latifolia below its minimum temperature?

It tolerates winter lows to about −15 to −10 °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.