Cold hardiness & minimum temperature

Is Roman Wormwood (Artemisia pontica)cold hardy? Hardiness zone & min temp

Also called Roman Wormwood, Lesser Absinthe, Pontic Wormwood.

More about roman wormwood

About Roman Wormwood

Artemisia pontica · also called Roman Wormwood, Lesser Absinthe · herb

Roman Wormwood is a compact, spreading subshrub with silvery-grey, feathery aromatic foliage historically used in vermouth and absinthe production. It spreads gradually via rhizomes to form dense low mats. Exceptionally cold-hardy and drought-tolerant; thrives in lean, dry soils in full sun. Ideal for herb gardens, dry borders, and gravel plantings.

Cold limit: USDA 4–8 · RHS H6 (-30°C to 35°C)

Watch for — Root rot in wet soil: Heavy clay or poorly drained sites cause root and crown rot, especially in winter. Plant in raised beds or improve drainage with grit before planting.

What roman wormwood's hardiness rating actually means

Yes — roman wormwood is genuinely cold hardy. Rated RHS H6 and USDA 4–8, it lives outdoors all year and needs winter cold rather than protection from it. Its RHS rating of H6 means: Hardy throughout the UK and northern Europe. On the US scale that maps to USDA 4–8 — 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 about −20 to −15 °C. Roman Wormwood is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for roman wormwood as it gets too cold:

It tolerates winter lows to about −20 to −15 °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 roman wormwood go outside or overwinter — and where?

Plant it out within USDA 4–8 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 roman wormwood can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H6 figure above.

Roman Wormwood hardiness — frequently asked questions

Is roman wormwood cold hardy?

Yes — roman wormwood is genuinely cold hardy. Rated RHS H6 and USDA 4–8, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Roman Wormwood is hardy across USDA 4–8; 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 roman wormwood can survive?

Minimum survivable temperature is roughly about −20 to −15 °C. Roman Wormwood is built for winter — once established it takes hard frost and snow in its stride.

What hardiness zone is roman wormwood?

Roman Wormwood is rated USDA 4–8 and RHS H6 — Hardy throughout the UK and northern Europe.

Can roman wormwood survive winter outside?

Plant it out within USDA 4–8 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 roman wormwood below its minimum temperature?

It tolerates winter lows to about −20 to −15 °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.