Cold hardiness & minimum temperature

Is Rayed Tansy (Tanacetum macrophyllum)cold hardy? Hardiness zone & min temp

Also called Rayed Tansy, Large-leaved Tansy, Balkan Tansy.

More about rayed tansy

About Rayed Tansy

Tanacetum macrophyllum · also called Rayed Tansy, Large-leaved Tansy · herb

Rayed Tansy is a robust, tall-growing perennial from the Balkans and Turkey, producing large, pinnate, aromatic bright-green leaves and flat corymbs of small white daisy flowers in summer. Notably larger-leaved than most Tanacetum relatives, it has historic uses as an insect repellent herb. It tolerates partial shade and moister soils than its silver-leaved relatives, suiting woodland edges and wilder gardens.

Cold limit: USDA 4–9 · RHS H7 (-20 to 30°C)

What rayed tansy's hardiness rating actually means

Yes — rayed tansy is genuinely cold hardy. Rated RHS H7 and USDA 4–9, 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 4–9 — 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. Rayed Tansy is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for rayed tansy 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 rayed tansy go outside or overwinter — and where?

Plant it out within USDA 4–9 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 rayed tansy can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H7 figure above.

Rayed Tansy hardiness — frequently asked questions

Is rayed tansy cold hardy?

Yes — rayed tansy is genuinely cold hardy. Rated RHS H7 and USDA 4–9, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Rayed Tansy is hardy across USDA 4–9; 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 rayed tansy can survive?

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

What hardiness zone is rayed tansy?

Rayed Tansy is rated USDA 4–9 and RHS H7 — Hardy in the severest European continental winters.

Can rayed tansy survive winter outside?

Plant it out within USDA 4–9 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 rayed tansy 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.