Cold hardiness & minimum temperature

Is Rotala nanjenshan (Rotala nanjenshan)cold hardy? Hardiness zone & min temp

Also called Nanjenshan Rotala, Taiwan Rotala.

More about rotala nanjenshan

About Rotala nanjenshan

Rotala nanjenshan · also called Nanjenshan Rotala, Taiwan Rotala · tropical

An aquascaping stem plant of Taiwanese origin, often sold under the Rotala/Mayaca trade name, with very fine needle-like leaves in dense whorls of green tinged orange-pink at the tips. It forms feathery, compact bushes under strong light and CO2, making a soft-textured midground or background accent in high-tech planted aquariums.

Cold limit: USDA Not applicable (tropical aquarium plant grown indoors in heated water) (20-28°C)

What rotala nanjenshan's hardiness rating actually means

Rotala nanjenshan 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 H1b means: Sub-tropical — a normal warm home is fine, but it cannot go outside in a cool season. On the US scale that maps to USDA Not applicable (tropical aquarium plant grown indoors in heated water) — 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 °C (sustained cold below this is damaging). Rotala nanjenshan has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

Concretely, for rotala nanjenshan as it gets too cold:

Below about about 10 °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 rotala nanjenshan go outside or overwinter — and where?

It can holiday outdoors in summer once nights are reliably above 10 °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 rotala nanjenshan can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H1b figure above.

Rotala nanjenshan hardiness — frequently asked questions

Is rotala nanjenshan cold hardy?

Rotala nanjenshan 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. Rotala nanjenshan can only live outside year-round in genuinely frost-free climates (roughly USDA Not applicable (tropical aquarium plant grown indoors in heated water)); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature rotala nanjenshan can survive?

What hardiness zone is rotala nanjenshan?

Rotala nanjenshan is rated USDA Not applicable (tropical aquarium plant grown indoors in heated water) and RHS H1b — Sub-tropical — a normal warm home is fine, but it cannot go outside in a cool season.

Can rotala nanjenshan survive winter outside?

It can holiday outdoors in summer once nights are reliably above 10 °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 rotala nanjenshan below its minimum temperature?

Below about about 10 °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.