Cold hardiness & minimum temperature

Is Fringed Coreopsis (Coreopsis integrifolia)cold hardy? Hardiness zone & min temp

Also called Fringed Coreopsis, Cutleaf Coreopsis.

More about fringed coreopsis

About Fringed Coreopsis

Coreopsis integrifolia · also called Fringed Coreopsis, Cutleaf Coreopsis · flowering

Fringed Coreopsis is a southeastern US native perennial producing golden-yellow daisy-like flowers in autumn. It thrives in full sun and tolerates poor, dry soils once established. Deer-resistant and pollinator-friendly, it is an excellent choice for naturalistic borders, rain gardens, and meadow plantings across USDA zones 6–9.

Cold limit: USDA 6-9 · RHS H5 (−15°C to 35°C)

Watch for — Crown rot in poorly drained soil: Crowns rot at the base when soil remains waterlogged over winter. Always plant in well-draining positions; raise beds or add grit if drainage is suspect. Dividing crowns every 3–4 years also improves plant vigour.

What fringed coreopsis's hardiness rating actually means

Yes — fringed coreopsis is genuinely cold hardy. Rated RHS H5 and USDA 6-9, it lives outdoors all year and needs winter cold rather than protection from it. Its RHS rating of H5 means: Hardy in most of the UK and in cold winters. On the US scale that maps to USDA 6-9 — 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 −15 to −10 °C. Fringed Coreopsis is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for fringed coreopsis as it gets too cold:

It tolerates winter lows to about −15 to −10 °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 fringed coreopsis go outside or overwinter — and where?

Plant it out within USDA 6-9 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 fringed coreopsis can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H5 figure above.

Fringed Coreopsis hardiness — frequently asked questions

Is fringed coreopsis cold hardy?

Yes — fringed coreopsis is genuinely cold hardy. Rated RHS H5 and USDA 6-9, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Fringed Coreopsis is hardy across USDA 6-9; 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 fringed coreopsis can survive?

Minimum survivable temperature is roughly about −15 to −10 °C. Fringed Coreopsis is built for winter — once established it takes hard frost and snow in its stride.

What hardiness zone is fringed coreopsis?

Fringed Coreopsis is rated USDA 6-9 and RHS H5 — Hardy in most of the UK and in cold winters.

Can fringed coreopsis survive winter outside?

Plant it out within USDA 6-9 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 fringed coreopsis below its minimum temperature?

It tolerates winter lows to about −15 to −10 °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.