Cold hardiness & minimum temperature

Is Overlooked Lagenandra (Lagenandra praetermissa)cold hardy? Hardiness zone & min temp

Also called Praetermissa Lagenandra.

More about overlooked lagenandra

About Overlooked Lagenandra

Lagenandra praetermissa · also called Praetermissa Lagenandra · tropical

Lagenandra praetermissa is a rare Sri Lankan rheophytic aroid closely related to Cryptocoryne, valued by aquarists and paludarium keepers for its elliptic, deep-green leaves. It thrives semi-submerged in high humidity and soft water. Toxic to pets due to calcium oxalate crystals inherent in the Araceae family.

Cold limit: USDA 12-13 (indoor/aquatic only) · RHS H1a (22-28°C)

What overlooked lagenandra's hardiness rating actually means

Overlooked Lagenandra 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 H1a means: Tropical — needs a heated room or greenhouse; no frost tolerance whatsoever. On the US scale that maps to USDA 12-13 (indoor/aquatic only) — 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 above about 15 °C (warm, never cold). Overlooked Lagenandra has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

Concretely, for overlooked lagenandra as it gets too cold:

Below about above about 15 °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 overlooked lagenandra go outside or overwinter — and where?

It can holiday outdoors in summer once nights are reliably above above 15 °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 overlooked lagenandra can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H1a figure above.

Overlooked Lagenandra hardiness — frequently asked questions

Is overlooked lagenandra cold hardy?

Overlooked Lagenandra 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. Overlooked Lagenandra can only live outside year-round in genuinely frost-free climates (roughly USDA 12-13 (indoor/aquatic only)); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature overlooked lagenandra can survive?

Minimum survivable temperature is roughly above about 15 °C (warm, never cold). Overlooked Lagenandra has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

What hardiness zone is overlooked lagenandra?

Overlooked Lagenandra is rated USDA 12-13 (indoor/aquatic only) and RHS H1a — Tropical — needs a heated room or greenhouse; no frost tolerance whatsoever.

Can overlooked lagenandra survive winter outside?

It can holiday outdoors in summer once nights are reliably above above 15 °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 overlooked lagenandra below its minimum temperature?

Below about above about 15 °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.