Cold hardiness & minimum temperature

Is Brazilian Micro Sword (Lilaeopsis brasiliensis)cold hardy? Hardiness zone & min temp

Also called Micro Sword, Carpet Grass, Brazilian Micro Sword Plant.

More about brazilian micro sword

About Brazilian Micro Sword

Lilaeopsis brasiliensis · also called Micro Sword, Carpet Grass · tropical

Lilaeopsis brasiliensis is a small, grass-like aquatic plant that forms a vivid-green lawn carpet in aquarium foregrounds. Native to South America, it grows via creeping runners and is a popular, moderately demanding carpet plant. Not listed as toxic by the ASPCA; considered pet-safe for cats, dogs, and aquarium inhabitants.

Cold limit: USDA 9–12 (can grow in outdoor bog or shallow pond edges in warm climates) · RHS H1c (20–28°C)

What brazilian micro sword's hardiness rating actually means

Brazilian Micro Sword 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 9–12 (can grow in outdoor bog or shallow pond edges in warm climates) — 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). Brazilian Micro Sword has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

Concretely, for brazilian micro sword 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 brazilian micro sword 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 brazilian micro sword can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H1c figure above.

Brazilian Micro Sword hardiness — frequently asked questions

Is brazilian micro sword cold hardy?

Brazilian Micro Sword 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. Brazilian Micro Sword can only live outside year-round in genuinely frost-free climates (roughly USDA 9–12 (can grow in outdoor bog or shallow pond edges in warm climates)); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature brazilian micro sword can survive?

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

What hardiness zone is brazilian micro sword?

Brazilian Micro Sword is rated USDA 9–12 (can grow in outdoor bog or shallow pond edges in warm climates) and RHS H1c — Warm-temperate — can summer outdoors but must come in well before the first frost.

Can brazilian micro sword 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 brazilian micro sword 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.