Cold hardiness & minimum temperature

Is Lance-leaved Sundew (Drosera adelae)cold hardy? Hardiness zone & min temp

Also called Lance-leaved sundew, Lance-leaf sundew, Sword sundew.

More about lance-leaved sundew

About Lance-leaved Sundew

Drosera adelae · also called Lance-leaved sundew, Lance-leaf sundew · houseplant

Drosera adelae, the lance-leaved sundew, is a beginner-friendly carnivorous houseplant from Queensland, Australia. Its sword-shaped leaves are covered in glistening, sticky tentacles that trap small insects. Grow it in wet sphagnum, bright light, and pure rain or distilled water, with no dormancy. Not ASPCA-listed; treat as mildly toxic and check with a vet.

Cold limit: USDA 9b-11 outdoors (tender tropical; grown as a houseplant or in a greenhouse/terrarium in cooler climates) (13-29C)

Watch for — Blackening leaves: Caused by overfeeding (rotting prey), letting the media dry out, or cold/heat stress. Remove rotting leaves, keep media wet, hold 55-85F, and feed only tiny insects sparingly.

What lance-leaved sundew's hardiness rating actually means

Lance-leaved 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 9b-11 outdoors (tender tropical; grown as a houseplant or in a greenhouse/terrarium in cooler 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). Lance-leaved Sundew has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

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

Lance-leaved Sundew hardiness — frequently asked questions

Is lance-leaved sundew cold hardy?

Lance-leaved 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. Lance-leaved Sundew can only live outside year-round in genuinely frost-free climates (roughly USDA 9b-11 outdoors (tender tropical; grown as a houseplant or in a greenhouse/terrarium in cooler climates)); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature lance-leaved sundew can survive?

What hardiness zone is lance-leaved sundew?

Lance-leaved Sundew is rated USDA 9b-11 outdoors (tender tropical; grown as a houseplant or in a greenhouse/terrarium in cooler climates) and RHS H1b — Sub-tropical — a normal warm home is fine, but it cannot go outside in a cool season.

Can lance-leaved 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 lance-leaved 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.