Cold hardiness & minimum temperature

Is Ord River Sundew (Drosera ordensis)cold hardy? Hardiness zone & min temp

Also called Ord River sundew.

More about ord river sundew

About Ord River Sundew

Drosera ordensis · also called Ord River sundew · tropical

Drosera ordensis is a tropical carnivorous sundew in the petiolaris complex, endemic to the Ord River catchment area of the Kimberley region, Western Australia, where it colonises seasonally inundated red sandy soils and rocky outcrops. Like all petiolaris group sundews it follows a pronounced monsoon cycle — growing vigorously in the hot wet season and retreating to the rhizome in the warm dry season. The single most critical care point is to maintain warmth year-round (never below 15 °C) even during the drier rest period, as cold combined with moisture triggers fatal rot. Drosera is not listed as toxic to cats or dogs by the ASPCA and is considered non-toxic to pets.

Cold limit: USDA 10-12 (indoor in most climates) · RHS H1b (20–40 °C (growing); 18–28 °C (rest))

Watch for — Rhizome rot after the monsoon season: Reducing watering too slowly when the plant enters its dry rest, especially at lower temperatures, promotes Pythium and other root pathogens. Taper watering gradually over 2–3 weeks as temperatures rise towards the end of the wet season in cultivation.

What ord river sundew's hardiness rating actually means

Ord River Sundew 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 10-12 (indoor in most 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 10 °C (sustained cold below this is damaging). Ord River Sundew has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

Concretely, for ord river sundew 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 ord river sundew 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 ord river sundew can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H1b figure above.

Ord River Sundew hardiness — frequently asked questions

Is ord river sundew cold hardy?

Ord River Sundew 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. Ord River Sundew can only live outside year-round in genuinely frost-free climates (roughly USDA 10-12 (indoor in most climates)); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature ord river sundew can survive?

What hardiness zone is ord river sundew?

Ord River Sundew is rated USDA 10-12 (indoor in most climates) and RHS H1b — Sub-tropical — a normal warm home is fine, but it cannot go outside in a cool season.

Can ord river sundew 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 ord river sundew 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.