Cold hardiness & minimum temperature

Is Derby Sundew (Drosera derbyensis)cold hardy? Hardiness zone & min temp

Also called Derby sundew.

More about derby sundew

About Derby Sundew

Drosera derbyensis · also called Derby sundew · tropical

Drosera derbyensis is a petiolaris complex sundew named after Derby in the West Kimberley region of Western Australia, where it inhabits seasonally flooded sandy flats and grasslands subject to the intense monsoon climate. It is closely related to Drosera ordensis and Drosera kenneallyi, sharing their requirement for a pronounced hot wet growing season and a warm, distinctly drier rest period. The most critical care point is that this species must be kept warm throughout the year — minimum 18 °C even in the dry rest — as cold and wet in combination is rapidly lethal to the rhizome. 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 — Crown and rhizome rot: The most common cause of plant death in cultivation. Cool temperatures combined with wet soil destroy the rhizome within weeks. Ensure the minimum temperature stays above 18 °C and drastically reduce watering as soon as the plant begins its rest phase.

What derby sundew's hardiness rating actually means

Derby 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). Derby Sundew has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

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

Derby Sundew hardiness — frequently asked questions

Is derby sundew cold hardy?

Derby 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. Derby 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 derby sundew can survive?

Minimum survivable temperature is roughly about 10 °C (sustained cold below this is damaging). Derby Sundew has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

What hardiness zone is derby sundew?

Derby 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 derby 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 derby 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.