Cold hardiness & minimum temperature

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

Also called Albert Greenberg Tropical Waterlily.

More about nymphaea 'albert greenberg'

About Nymphaea 'Albert Greenberg'

Nymphaea 'Albert Greenberg' · also called Albert Greenberg Tropical Waterlily · flowering

Nymphaea 'Albert Greenberg' is a tropical day-blooming waterlily prized for warm sunset-toned flowers blending pink, yellow and orange, set over heavily mottled maroon-and-green pads. Exceptionally free-flowering and tolerant of cooler conditions than most tropicals, it is grown as a summer or glasshouse pond plant in the US and UK, overwintered frost-free.

Cold limit: USDA 9-11 (tender tropical; annual or overwinter frost-free in cooler zones) · RHS H1c (20-30°C)

Watch for — Sluggish start in cool water: Even this tolerant tropical needs warmth to get going. Plant out once the pond warms in early summer rather than in cold spring water.

What nymphaea 'albert greenberg''s hardiness rating actually means

Nymphaea 'Albert Greenberg' is not cold hardy. It is a tropical houseplant that dies if it is left out through frost — there is no zone where it overwinters outdoors in a UK or cold-US climate. Its RHS rating of H1c means: Warm-temperate — can summer outdoors but must come in well before the first frost. On the US scale that maps to USDA 9-11 (tender tropical; annual or overwinter frost-free in cooler zones) — 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 5 °C (and never frost). Nymphaea 'Albert Greenberg' has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

Concretely, for nymphaea 'albert greenberg' as it gets too cold:

Below about about 5 °C, growth stalls and the leaves start to show cold stress — dark, water-soaked, or yellowing patches.
A single light frost blackens the foliage; a hard freeze kills the whole plant, roots included, and it does not recover.
Even a cold, draughty windowsill or an unheated porch in winter can be enough to damage it permanently.

Can nymphaea 'albert greenberg' go outside or overwinter — and where?

It can holiday outdoors in summer once nights are reliably above 5 °C, in shade or dappled light, hardened off gradually.
Bring it back indoors well before the first autumn frost — do not wait for a frost warning, move it when nights drop toward 10-12 °C.
It will never overwinter outside in a temperate climate; the indoors is its winter home, full stop.

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 'albert greenberg' can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H1c figure above.

Nymphaea 'Albert Greenberg' hardiness — frequently asked questions

Is nymphaea 'albert greenberg' cold hardy?

Nymphaea 'Albert Greenberg' is not cold hardy. It is a tropical houseplant that dies if it is left out through frost — there is no zone where it overwinters outdoors in a UK or cold-US climate. Indoor-only in almost every home. Nymphaea 'Albert Greenberg' can only live outside year-round in genuinely frost-free climates (roughly USDA 9-11 (tender tropical; annual or overwinter frost-free in cooler zones)); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature nymphaea 'albert greenberg' can survive?

Minimum survivable temperature is roughly about 5 °C (and never frost). Nymphaea 'Albert Greenberg' has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

What hardiness zone is nymphaea 'albert greenberg'?

Nymphaea 'Albert Greenberg' is rated USDA 9-11 (tender tropical; annual or overwinter frost-free in cooler zones) and RHS H1c — Warm-temperate — can summer outdoors but must come in well before the first frost.

Can nymphaea 'albert greenberg' survive winter outside?

It can holiday outdoors in summer once nights are reliably above 5 °C, in shade or dappled light, hardened off gradually. Bring it back indoors well before the first autumn frost — do not wait for a frost warning, move it when nights drop toward 10-12 °C. It will never overwinter outside in a temperate climate; the indoors is its winter home, full stop.

What happens to nymphaea 'albert greenberg' below its minimum temperature?

Below about about 5 °C, growth stalls and the leaves start to show cold stress — dark, water-soaked, or yellowing patches. A single light frost blackens the foliage; a hard freeze kills the whole plant, roots included, and it does not recover. Even a cold, draughty windowsill or an unheated porch in winter can be enough to damage it permanently.