Cold hardiness & minimum temperature

Is Hairy Coreopsis (Coreopsis pubescens)cold hardy? Hardiness zone & min temp

Also called Hairy Coreopsis, Star Tickseed.

More about hairy coreopsis

About Hairy Coreopsis

Coreopsis pubescens · also called Hairy Coreopsis, Star Tickseed · flowering

Hairy Coreopsis is a native perennial wildflower of the southeastern US, named for the fine soft hairs covering its stems and leaves. It produces cheerful golden-yellow daisy flowers on branching stems from mid-summer to early autumn. Well adapted to dry, open woodlands and rocky soils, it tolerates heat and humidity better than many coreopsis species.

Cold limit: USDA 5-9 · RHS H6 (-15–38°C)

What hairy coreopsis's hardiness rating actually means

Yes — hairy coreopsis is genuinely cold hardy. Rated RHS H6 and USDA 5-9, 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 5-9 — 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. Hairy Coreopsis is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for hairy coreopsis 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 hairy coreopsis go outside or overwinter — and where?

Plant it out within USDA 5-9 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 hairy coreopsis can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H6 figure above.

Hairy Coreopsis hardiness — frequently asked questions

Is hairy coreopsis cold hardy?

Yes — hairy coreopsis is genuinely cold hardy. Rated RHS H6 and USDA 5-9, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Hairy Coreopsis is hardy across USDA 5-9; 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 hairy coreopsis can survive?

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

What hardiness zone is hairy coreopsis?

Hairy Coreopsis is rated USDA 5-9 and RHS H6 — Hardy throughout the UK and northern Europe.

Can hairy coreopsis survive winter outside?

Plant it out within USDA 5-9 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 hairy coreopsis 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.