Cold hardiness & minimum temperature

Is Sawtooth Venus flytrap (Dionaea muscipula 'Sawtooth')cold hardy? Hardiness zone & min temp

Also called Sawtooth Venus flytrap, Sawtooth flytrap.

More about sawtooth venus flytrap

About Sawtooth Venus flytrap

Dionaea muscipula 'Sawtooth' · also called Sawtooth Venus flytrap, Sawtooth flytrap · houseplant

A registered 2000 cultivar with dramatically fringed traps whose teeth are minutely divided two or three times, creating a saw-like margin. Grow in full sun with pure, mineral-free water and a nutrient-poor sphagnum-perlite mix. Requires a winter dormancy of 2–4 months at cool temperatures. ASPCA-listed non-toxic to cats, dogs, and horses.

Cold limit: USDA 5–8 · RHS H3 (5–35°C (growing season 18–30°C; dormancy 2–10°C))

Watch for — Winter decline (no new growth): Venus flytraps require 2–4 months of winter dormancy at 2–10°C with reduced watering. A plant denied dormancy weakens over successive years. Move to an unheated greenhouse, cold frame, or refrigerator for the dormancy period.

What sawtooth venus flytrap's hardiness rating actually means

Sawtooth Venus flytrap 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 5–8 — 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. Sawtooth Venus flytrap shrugs off cold nights but a real, sustained freeze will kill it.

Concretely, for sawtooth venus flytrap 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 sawtooth venus flytrap go outside or overwinter — and where?

It can live outside year-round only in the mildest, most sheltered part of USDA 5–8 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 sawtooth venus flytrap 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 sawtooth venus flytrap

Sawtooth Venus flytrap 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.

Sawtooth Venus flytrap hardiness — frequently asked questions

Is sawtooth venus flytrap cold hardy?

Sawtooth Venus flytrap 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 5–8 (and sheltered UK gardens) sawtooth venus flytrap can stay out; in colder areas it must be lifted, brought in, or treated as a frost-tender plant.

What is the minimum temperature sawtooth venus flytrap can survive?

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

What hardiness zone is sawtooth venus flytrap?

Sawtooth Venus flytrap is rated USDA 5–8 and RHS H3 — Half-hardy — comes through mild UK winters outside but is killed by a hard freeze.

Can sawtooth venus flytrap survive winter outside?

It can live outside year-round only in the mildest, most sheltered part of USDA 5–8 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 sawtooth venus flytrap 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.