Cold hardiness & minimum temperature

Is Wild Teasel (Dipsacus fullonum)cold hardy? Hardiness zone & min temp

Also called Wild Teasel, Common Teasel, Fuller's Teasel.

More about wild teasel

About Wild Teasel

Dipsacus fullonum · also called Wild Teasel, Common Teasel · flowering

Native to Britain, Ireland, and mainland Europe, wild teasel is a robust biennial of roadsides, riverbanks, and rough grassland, growing a prickly basal rosette in year one and a towering spiny stem with cone-shaped flowerheads in year two. It thrives in full sun to partial shade on moist, fertile soils including heavy clay, and is prized in wildlife gardens for its violet-band flowers that attract bees and its architectural seedheads that goldfinches work through autumn and winter. The single most critical care note is that it self-seeds prolifically and can naturalise aggressively, so deadhead promptly if spread is unwanted. No toxicity to dogs, cats, or horses has been reported for this species.

Cold limit: USDA 4-8 · RHS H7 (-20°C to 30°C)

What wild teasel's hardiness rating actually means

Yes — wild teasel is genuinely cold hardy. Rated RHS H7 and USDA 4-8, it lives outdoors all year and needs winter cold rather than protection from it. Its RHS rating of H7 means: Hardy in the severest European continental winters. On the US scale that maps to USDA 4-8 — 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 below about −20 °C. Wild Teasel is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for wild teasel as it gets too cold:

It tolerates winter lows to about −20 °C once established.
Below its rated zone, the visible damage is browned or blackened top growth and, in the worst case, a killed crown or root.
First-year, newly planted, or container-grown specimens are noticeably less hardy than established garden plants — the roots are exposed.

Can wild teasel go outside or overwinter — and where?

Plant it out within USDA 4-8 and it overwinters with little or no help.
It does not want to come indoors — a warm winter room actually weakens a hardy plant by denying it dormancy.
The real risks in its range are waterlogging, wind-rock on young plants, and a late hard frost on new growth — not ordinary winter cold.

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 wild teasel can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H7 figure above.

Wild Teasel hardiness — frequently asked questions

Is wild teasel cold hardy?

Yes — wild teasel is genuinely cold hardy. Rated RHS H7 and USDA 4-8, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Wild Teasel is hardy across USDA 4-8; it belongs in the ground or a frost-proof container, not on a windowsill, and many types actively need a cold winter to perform.

What is the minimum temperature wild teasel can survive?

Minimum survivable temperature is roughly below about −20 °C. Wild Teasel is built for winter — once established it takes hard frost and snow in its stride.

What hardiness zone is wild teasel?

Wild Teasel is rated USDA 4-8 and RHS H7 — Hardy in the severest European continental winters.

Can wild teasel survive winter outside?

Plant it out within USDA 4-8 and it overwinters with little or no help. It does not want to come indoors — a warm winter room actually weakens a hardy plant by denying it dormancy. The real risks in its range are waterlogging, wind-rock on young plants, and a late hard frost on new growth — not ordinary winter cold.

What happens to wild teasel below its minimum temperature?

It tolerates winter lows to about −20 °C once established. Below its rated zone, the visible damage is browned or blackened top growth and, in the worst case, a killed crown or root. First-year, newly planted, or container-grown specimens are noticeably less hardy than established garden plants — the roots are exposed.