Cold hardiness & minimum temperature

Is Coreopsis 'Moonbeam' (Coreopsis verticillata 'Moonbeam')cold hardy? Hardiness zone & min temp

Also called Threadleaf coreopsis, Tickseed.

More about coreopsis 'moonbeam'

About Coreopsis 'Moonbeam'

Coreopsis verticillata 'Moonbeam' · also called Threadleaf coreopsis, Tickseed · flowering

Coreopsis 'Moonbeam' is an airy threadleaf perennial smothered in soft pale-yellow daisies from early summer to autumn above ferny foliage. Tough, drought-tolerant, and long-blooming, it spreads slowly into weed-suppressing drifts and feeds pollinators. ASPCA-listed as non-toxic to cats and dogs (Coreopsis spp.).

Cold limit: USDA 3-9 · RHS H7 (15-29°C)

Watch for — Crown / root rot: Wet, heavy, poorly drained soil — especially over winter — rots the crown; site in sharp drainage and avoid overwatering.

What coreopsis 'moonbeam''s hardiness rating actually means

Yes — coreopsis 'moonbeam' is genuinely cold hardy. Rated RHS H7 and USDA 3-9, 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 3-9 — 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 below about −20 °C. Coreopsis 'Moonbeam' is built for winter — once established it takes hard frost and snow in its stride.

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

Plant it out within USDA 3-9 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 coreopsis 'moonbeam' can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H7 figure above.

Coreopsis 'Moonbeam' hardiness — frequently asked questions

Is coreopsis 'moonbeam' cold hardy?

Yes — coreopsis 'moonbeam' is genuinely cold hardy. Rated RHS H7 and USDA 3-9, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Coreopsis 'Moonbeam' is hardy across USDA 3-9; 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 coreopsis 'moonbeam' can survive?

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

What hardiness zone is coreopsis 'moonbeam'?

Coreopsis 'Moonbeam' is rated USDA 3-9 and RHS H7 — Hardy in the severest European continental winters.

Can coreopsis 'moonbeam' survive winter outside?

Plant it out within USDA 3-9 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 coreopsis 'moonbeam' 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.