Cold hardiness & minimum temperature

Is Ludwigia palustris (Ludwigia palustris)cold hardy? Hardiness zone & min temp

Also called marsh purslane, water purslane.

More about ludwigia palustris

About Ludwigia palustris

Ludwigia palustris · also called marsh purslane, water purslane · tropical

Ludwigia palustris is a hardy stem plant for aquariums and paludariums, prized for olive-green to bronze-red foliage that deepens under strong light and CO2. It grows fast both submersed and emersed, tolerates a wide temperature range, and is a classic beginner red-stem. Trim and replant tops to keep it bushy and colourful.

Cold limit: USDA 4-10 (hardy marginal pond plant outdoors) · RHS H5 (18-28°C)

What ludwigia palustris's hardiness rating actually means

Yes — ludwigia palustris is genuinely cold hardy. Rated RHS H5 and USDA 4-10 (hardy marginal pond plant outdoors), 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 (hardy marginal pond plant outdoors) — 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. Ludwigia palustris is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for ludwigia palustris 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 ludwigia palustris go outside or overwinter — and where?

Plant it out within USDA 4-10 (hardy marginal pond plant outdoors) 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 ludwigia palustris can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H5 figure above.

Ludwigia palustris hardiness — frequently asked questions

Is ludwigia palustris cold hardy?

Yes — ludwigia palustris is genuinely cold hardy. Rated RHS H5 and USDA 4-10 (hardy marginal pond plant outdoors), it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Ludwigia palustris is hardy across USDA 4-10 (hardy marginal pond plant outdoors); 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 ludwigia palustris can survive?

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

What hardiness zone is ludwigia palustris?

Ludwigia palustris is rated USDA 4-10 (hardy marginal pond plant outdoors) and RHS H5 — Hardy in most of the UK and in cold winters.

Can ludwigia palustris survive winter outside?

Plant it out within USDA 4-10 (hardy marginal pond plant outdoors) 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 ludwigia palustris 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.