Cold hardiness & minimum temperature

Is Cat's-ear (Hypochaeris radicata)cold hardy? Hardiness zone & min temp

Also called Cat's-ear, Hairy Cat's-ear, False Dandelion, Flatweed.

More about cat's-ear

About Cat's-ear

Hypochaeris radicata · also called Cat's-ear, Hairy Cat's-ear · flowering

Hypochaeris radicata is a rosette-forming perennial native to grasslands, lawns, and disturbed ground across the UK and Europe, producing bright yellow dandelion-like flower heads on branched, scaly scapes from June to September. It closely resembles a dandelion but is distinguished by its branched stems and hairy, wavy-edged leaves. Extremely resilient and drought-tolerant, it thrives in poor, well-drained soils in full sun with minimal care. The ASPCA lists it as toxic to horses (causing stringhalt); its toxicity to cats and dogs is unconfirmed, so a mildly-toxic classification is applied.

Cold limit: USDA 4-8 · RHS H6 (-20 to 30 °C)

What cat's-ear's hardiness rating actually means

Yes — cat's-ear is genuinely cold hardy. Rated RHS H6 and USDA 4-8, it lives outdoors all year and needs winter cold rather than protection from it. Its RHS rating of H6 means: Hardy throughout the UK and northern Europe. 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 about −20 to −15 °C. Cat's-ear is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for cat's-ear as it gets too cold:

It tolerates winter lows to about −20 to −15 °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 cat's-ear 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 cat's-ear can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H6 figure above.

Cat's-ear hardiness — frequently asked questions

Is cat's-ear cold hardy?

Yes — cat's-ear is genuinely cold hardy. Rated RHS H6 and USDA 4-8, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Cat's-ear 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 cat's-ear can survive?

Minimum survivable temperature is roughly about −20 to −15 °C. Cat's-ear is built for winter — once established it takes hard frost and snow in its stride.

What hardiness zone is cat's-ear?

Cat's-ear is rated USDA 4-8 and RHS H6 — Hardy throughout the UK and northern Europe.

Can cat's-ear 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 cat's-ear below its minimum temperature?

It tolerates winter lows to about −20 to −15 °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.