Cold hardiness & minimum temperature

Is Edelweiss (Leontopodium alpinum)cold hardy? Hardiness zone & min temp

Also called Edelweiss.

More about edelweiss

About Edelweiss

Leontopodium alpinum · also called Edelweiss · flowering

Edelweiss is an iconic woolly alpine perennial from high-altitude meadows and limestone rocks in the Alps and Pyrenees. Its distinctive star-shaped flower heads — creamy-white woolly bracts surrounding tiny florets — appear in summer. It prefers lean, alkaline, extremely well-drained soil and full sun, making it a classic rock garden and alpine trough plant.

Cold limit: USDA 4-7 · RHS H7 (-30°C to 20°C)

Watch for — Winter wet and crown rot: The most common cause of loss in UK and similar climates. Prolonged winter rain saturating woolly foliage causes fungal rot. Protect container plants under a cold-frame or place a pane of glass overhead to deflect rain while maintaining air flow.

What edelweiss's hardiness rating actually means

Yes — edelweiss is genuinely cold hardy. Rated RHS H7 and USDA 4-7, 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 4-7 — 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. Edelweiss is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for edelweiss 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 edelweiss go outside or overwinter — and where?

Plant it out within USDA 4-7 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 edelweiss can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H7 figure above.

Edelweiss hardiness — frequently asked questions

Is edelweiss cold hardy?

Yes — edelweiss is genuinely cold hardy. Rated RHS H7 and USDA 4-7, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Edelweiss is hardy across USDA 4-7; 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 edelweiss can survive?

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

What hardiness zone is edelweiss?

Edelweiss is rated USDA 4-7 and RHS H7 — Hardy in the severest European continental winters.

Can edelweiss survive winter outside?

Plant it out within USDA 4-7 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 edelweiss 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.