Cold hardiness & minimum temperature

Is Waterwheel Plant (Aldrovanda vesiculosa)cold hardy? Hardiness zone & min temp

Also called waterwheel plant.

More about waterwheel plant

About Waterwheel Plant

Aldrovanda vesiculosa · also called waterwheel plant · houseplant

The world's only aquatic snap-trap carnivore, related to Venus flytraps, floating rootless in warm, tea-coloured, tannin-rich water. Whorls of tiny snap traps arranged like a waterwheel catch aquatic invertebrates. Requires very warm summers, mineral-free acidic water, and ample sun. Forms dormant turions to overwinter.

Cold limit: USDA 6–10 (overwinters as turions in zones 6–7; actively grows zones 8–10) · RHS H4 (Water 20–32°C for active growth; tolerates down to 4°C as turions)

Watch for — Failure to thrive in cold water: Below 18°C (65°F) growth stalls and the plant may not trap effectively. In temperate climates this species only grows actively during warm summer months; bring indoors under grow lights if water temperature drops.

What waterwheel plant's hardiness rating actually means

Yes — waterwheel plant is genuinely cold hardy. Rated RHS H4 and USDA 6–10 (overwinters as turions in zones 6–7; actively grows zones 8–10), it lives outdoors all year and needs winter cold rather than protection from it. Its RHS rating of H4 means: Hardy in an average winter across much of the temperate world. On the US scale that maps to USDA 6–10 (overwinters as turions in zones 6–7; actively grows zones 8–10) — 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 −10 to −5 °C. Waterwheel Plant is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for waterwheel plant as it gets too cold:

It tolerates winter lows to about −10 to −5 °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 waterwheel plant go outside or overwinter — and where?

Plant it out within USDA 6–10 (overwinters as turions in zones 6–7; actively grows zones 8–10) 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 waterwheel plant can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H4 figure above.

Waterwheel Plant hardiness — frequently asked questions

Is waterwheel plant cold hardy?

Yes — waterwheel plant is genuinely cold hardy. Rated RHS H4 and USDA 6–10 (overwinters as turions in zones 6–7; actively grows zones 8–10), it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Waterwheel Plant is hardy across USDA 6–10 (overwinters as turions in zones 6–7; actively grows zones 8–10); 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 waterwheel plant can survive?

Minimum survivable temperature is roughly about −10 to −5 °C. Waterwheel Plant is built for winter — once established it takes hard frost and snow in its stride.

What hardiness zone is waterwheel plant?

Waterwheel Plant is rated USDA 6–10 (overwinters as turions in zones 6–7; actively grows zones 8–10) and RHS H4 — Hardy in an average winter across much of the temperate world.

Can waterwheel plant survive winter outside?

Plant it out within USDA 6–10 (overwinters as turions in zones 6–7; actively grows zones 8–10) 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 waterwheel plant below its minimum temperature?

It tolerates winter lows to about −10 to −5 °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.