Cold hardiness & minimum temperature

Is Nymphaea 'Gonnere' (Nymphaea 'Gonnere')cold hardy? Hardiness zone & min temp

Also called Snowball Waterlily, Gonnere Waterlily.

More about nymphaea 'gonnere'

About Nymphaea 'Gonnere'

Nymphaea 'Gonnere' · also called Snowball Waterlily, Gonnere Waterlily · flowering

Nymphaea 'Gonnere' is a hardy white waterlily prized for its fully double, ball-shaped blooms with dozens of pure-white petals. A vigorous but compact grower, it thrives rooted in pond mud under full sun, spreading floating green pads across the surface. It is grown in still ornamental ponds across temperate zones in the US and UK.

Cold limit: USDA 4-11 (hardy, overwinters in deep ponds below ice line) · RHS H5 (15-30°C)

What nymphaea 'gonnere''s hardiness rating actually means

Yes — nymphaea 'gonnere' is genuinely cold hardy. Rated RHS H5 and USDA 4-11 (hardy, overwinters in deep ponds below ice line), 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 4-11 (hardy, overwinters in deep ponds below ice line) — 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. Nymphaea 'Gonnere' is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for nymphaea 'gonnere' 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 nymphaea 'gonnere' go outside or overwinter — and where?

Plant it out within USDA 4-11 (hardy, overwinters in deep ponds below ice line) 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 nymphaea 'gonnere' can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H5 figure above.

Nymphaea 'Gonnere' hardiness — frequently asked questions

Is nymphaea 'gonnere' cold hardy?

Yes — nymphaea 'gonnere' is genuinely cold hardy. Rated RHS H5 and USDA 4-11 (hardy, overwinters in deep ponds below ice line), it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Nymphaea 'Gonnere' is hardy across USDA 4-11 (hardy, overwinters in deep ponds below ice line); 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 nymphaea 'gonnere' can survive?

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

What hardiness zone is nymphaea 'gonnere'?

Nymphaea 'Gonnere' is rated USDA 4-11 (hardy, overwinters in deep ponds below ice line) and RHS H5 — Hardy in most of the UK and in cold winters.

Can nymphaea 'gonnere' survive winter outside?

Plant it out within USDA 4-11 (hardy, overwinters in deep ponds below ice line) 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 nymphaea 'gonnere' 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.