Cold hardiness & minimum temperature

Is Pink Sundew (Drosera capillaris)cold hardy? Hardiness zone & min temp

Also called pink sundew, hair-leaf sundew.

More about pink sundew

About Pink Sundew

Drosera capillaris · also called pink sundew, hair-leaf sundew · houseplant

Drosera capillaris is a small North American sundew native to wet coastal plain habitats from the southeastern United States through the Caribbean. It forms tight flat rosettes with spoon-shaped leaves bearing vivid red sticky tentacles and produces charming pink flowers on wiry scapes. It self-seeds freely and tolerates heat, making it an easy beginner carnivore.

Cold limit: USDA 7-10 · RHS H3 (10-35°C)

Watch for — Crown rot during winter: In cooler conditions with stagnant humidity, Botrytis can attack the growing point. Improve air circulation and remove dead tissue with sterile scissors.

What pink sundew's hardiness rating actually means

Pink Sundew is half-hardy (RHS H3). It survives a mild winter outdoors in a sheltered spot, but a hard frost kills it — so in colder zones it is lifted, potted, or grown as a tender plant. Its RHS rating of H3 means: Half-hardy — comes through mild UK winters outside but is killed by a hard freeze. On the US scale that maps to USDA 7-10 — 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 to 1 °C — a light, short frost only. Pink Sundew shrugs off cold nights but a real, sustained freeze will kill it.

Concretely, for pink sundew as it gets too cold:

Down to roughly about −5 to 1 °C it copes, especially if dry and sheltered.
A sustained hard frost collapses the top growth; whether it returns depends on whether the roots, crown or tubers froze.
Wet cold is far more lethal than dry cold for this plant — soggy, frozen soil is the usual killer.

Can pink sundew go outside or overwinter — and where?

It can live outside year-round only in the mildest, most sheltered part of USDA 7-10 or a frost-free UK microclimate.
In colder zones, grow it in a pot you can move under cover, or lift its tubers/roots and store them frost-free over winter.
A south-facing wall, free-draining soil and a dry winter position can push it a full zone hardier than the books suggest.

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 pink sundew can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H3 figure above.

Frost protection for borderline pink sundew

Pink Sundew is right on a hardiness edge in many gardens, so if you are pushing it, these measures buy it the margin it needs:

Mulch the crown or root zone deeply with bark, straw or leaf-mould before the first hard frost.
Move container plants against a warm wall or into an unheated but frost-free porch or greenhouse.
Fleece the top growth on the coldest nights, and keep it on the dry side — dry roots survive cold far better than wet ones.
Lift dahlia-type tubers or tender crowns after the first light frost blackens the foliage and store them somewhere cool but frost-free.

Pink Sundew hardiness — frequently asked questions

Is pink sundew cold hardy?

Pink Sundew is half-hardy (RHS H3). It survives a mild winter outdoors in a sheltered spot, but a hard frost kills it — so in colder zones it is lifted, potted, or grown as a tender plant. Borderline outdoors. In its mild end of USDA 7-10 (and sheltered UK gardens) pink sundew can stay out; in colder areas it must be lifted, brought in, or treated as a frost-tender plant.

What is the minimum temperature pink sundew can survive?

Minimum survivable temperature is roughly about −5 to 1 °C — a light, short frost only. Pink Sundew shrugs off cold nights but a real, sustained freeze will kill it.

What hardiness zone is pink sundew?

Pink Sundew is rated USDA 7-10 and RHS H3 — Half-hardy — comes through mild UK winters outside but is killed by a hard freeze.

Can pink sundew survive winter outside?

It can live outside year-round only in the mildest, most sheltered part of USDA 7-10 or a frost-free UK microclimate. In colder zones, grow it in a pot you can move under cover, or lift its tubers/roots and store them frost-free over winter. A south-facing wall, free-draining soil and a dry winter position can push it a full zone hardier than the books suggest.

How do I protect pink sundew from frost?

Mulch the crown or root zone deeply with bark, straw or leaf-mould before the first hard frost. Move container plants against a warm wall or into an unheated but frost-free porch or greenhouse. Fleece the top growth on the coldest nights, and keep it on the dry side — dry roots survive cold far better than wet ones. Lift dahlia-type tubers or tender crowns after the first light frost blackens the foliage and store them somewhere cool but frost-free.