Cold hardiness & minimum temperature

Is Autumn Catchfly (Silene schafta)cold hardy? Hardiness zone & min temp

Also called Autumn Catchfly, Schafta Campion.

More about autumn catchfly

About Autumn Catchfly

Silene schafta · also called Autumn Catchfly, Schafta Campion · flowering

Autumn Catchfly is a compact, clump-forming perennial from the Caucasus, prized for producing its vivid magenta-pink flowers from late summer well into autumn when most alpines have finished. It forms low tufts of hairy, mid-green leaves and is excellent for rock gardens, front-of-border positions, and alpine troughs where late-season colour is valuable.

Cold limit: USDA 4-9 · RHS H7 (-20°C to 28°C)

What autumn catchfly's hardiness rating actually means

Yes — autumn catchfly 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. Autumn Catchfly is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for autumn catchfly 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 autumn catchfly 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 autumn catchfly can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H7 figure above.

Autumn Catchfly hardiness — frequently asked questions

Is autumn catchfly cold hardy?

Yes — autumn catchfly 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. Autumn Catchfly 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 autumn catchfly can survive?

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

What hardiness zone is autumn catchfly?

Autumn Catchfly is rated USDA 4-9 and RHS H7 — Hardy in the severest European continental winters.

Can autumn catchfly 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 autumn catchfly 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.