Cold hardiness & minimum temperature

Is Beach Wormwood (Artemisia stelleriana)cold hardy? Hardiness zone & min temp

Also called Beach Wormwood, Dusty Miller, Oldwoman, Hoary Mugwort.

More about beach wormwood

About Beach Wormwood

Artemisia stelleriana · also called Beach Wormwood, Dusty Miller · herb

Beach Wormwood is a low-growing, spreading perennial prized for its deeply lobed, silvery-white felted foliage. Extremely cold-hardy and salt-tolerant, it thrives in lean, dry, sandy soils in full sun. Excellent as a ground cover or edging plant in coastal gardens. Drought-tolerant once established; avoid wet or heavy soils, which cause root rot.

Cold limit: USDA 3–7 · RHS H7 (-35°C to 35°C)

What beach wormwood's hardiness rating actually means

Yes — beach wormwood is genuinely cold hardy. Rated RHS H7 and USDA 3–7, 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 3–7 — 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. Beach Wormwood is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for beach wormwood 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 beach wormwood go outside or overwinter — and where?

Plant it out within USDA 3–7 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 beach wormwood can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H7 figure above.

Beach Wormwood hardiness — frequently asked questions

Is beach wormwood cold hardy?

Yes — beach wormwood is genuinely cold hardy. Rated RHS H7 and USDA 3–7, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Beach Wormwood is hardy across USDA 3–7; 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 beach wormwood can survive?

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

What hardiness zone is beach wormwood?

Beach Wormwood is rated USDA 3–7 and RHS H7 — Hardy in the severest European continental winters.

Can beach wormwood survive winter outside?

Plant it out within USDA 3–7 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 beach wormwood 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.