Cold hardiness & minimum temperature

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

Also called Yellow Waterlily, Chromatella Waterlily.

More about nymphaea 'chromatella'

About Nymphaea 'Chromatella'

Nymphaea 'Chromatella' · also called Yellow Waterlily, Chromatella Waterlily · flowering

Nymphaea 'Chromatella' (syn. 'Marliacea Chromatella') is a free-flowering hardy waterlily with soft canary-yellow, star-shaped blooms and handsome olive pads mottled with maroon. Tolerant and adaptable, it suits small to medium ponds, flowering reliably even in cooler conditions. Needs full sun, still water around 30-60 cm deep, and a heavy loam basket.

Cold limit: USDA 4-11 (hardy waterlily; overwinters as a submerged rhizome) · RHS H5 (15-30°C)

What nymphaea 'chromatella''s hardiness rating actually means

Yes — nymphaea 'chromatella' is genuinely cold hardy. Rated RHS H5 and USDA 4-11 (hardy waterlily; overwinters as a submerged rhizome), 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 waterlily; overwinters as a submerged rhizome) — 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 'Chromatella' is built for winter — once established it takes hard frost and snow in its stride.

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

Plant it out within USDA 4-11 (hardy waterlily; overwinters as a submerged rhizome) 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 'chromatella' can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H5 figure above.

Nymphaea 'Chromatella' hardiness — frequently asked questions

Is nymphaea 'chromatella' cold hardy?

Yes — nymphaea 'chromatella' is genuinely cold hardy. Rated RHS H5 and USDA 4-11 (hardy waterlily; overwinters as a submerged rhizome), it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Nymphaea 'Chromatella' is hardy across USDA 4-11 (hardy waterlily; overwinters as a submerged rhizome); 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 'chromatella' can survive?

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

What hardiness zone is nymphaea 'chromatella'?

Nymphaea 'Chromatella' is rated USDA 4-11 (hardy waterlily; overwinters as a submerged rhizome) and RHS H5 — Hardy in most of the UK and in cold winters.

Can nymphaea 'chromatella' survive winter outside?

Plant it out within USDA 4-11 (hardy waterlily; overwinters as a submerged rhizome) 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 'chromatella' 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.