Cold hardiness & minimum temperature

Is Arp Rosemary (Salvia rosmarinus 'Arp')cold hardy? Hardiness zone & min temp

Also called Hardy Rosemary.

More about arp rosemary

About Arp Rosemary

Salvia rosmarinus 'Arp' · also called Hardy Rosemary · herb

'Arp' is one of the hardiest rosemary cultivars, an upright evergreen with grey-green needle leaves and pale blue spring flowers that survives colder winters than most rosemary. It wants full sun and very sharp drainage, tolerates drought, and supplies aromatic, kitchen-ready foliage year-round in suitable climates.

Cold limit: USDA 6-10 (notably hardier than typical rosemary, which is usually zone 8+) · RHS H4 (10-27°C)

Watch for — Winter wet, not just cold: Even this hardy cultivar dies in cold, waterlogged soil; sharp drainage matters as much as low temperatures for getting it through winter.

What arp rosemary's hardiness rating actually means

Yes — arp rosemary is genuinely cold hardy. Rated RHS H4 and USDA 6-10 (notably hardier than typical rosemary, which is usually zone 8+), it lives outdoors all year and needs winter cold rather than protection from it. Its RHS rating of H4 means: Hardy in an average winter across much of the temperate world. On the US scale that maps to USDA 6-10 (notably hardier than typical rosemary, which is usually zone 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 −10 to −5 °C. Arp Rosemary is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for arp rosemary as it gets too cold:

It tolerates winter lows to about −10 to −5 °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 arp rosemary go outside or overwinter — and where?

Plant it out within USDA 6-10 (notably hardier than typical rosemary, which is usually zone 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 arp rosemary can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H4 figure above.

Arp Rosemary hardiness — frequently asked questions

Is arp rosemary cold hardy?

Yes — arp rosemary is genuinely cold hardy. Rated RHS H4 and USDA 6-10 (notably hardier than typical rosemary, which is usually zone 8+), it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Arp Rosemary is hardy across USDA 6-10 (notably hardier than typical rosemary, which is usually zone 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 arp rosemary can survive?

Minimum survivable temperature is roughly about −10 to −5 °C. Arp Rosemary is built for winter — once established it takes hard frost and snow in its stride.

What hardiness zone is arp rosemary?

Arp Rosemary is rated USDA 6-10 (notably hardier than typical rosemary, which is usually zone 8+) and RHS H4 — Hardy in an average winter across much of the temperate world.

Can arp rosemary survive winter outside?

Plant it out within USDA 6-10 (notably hardier than typical rosemary, which is usually zone 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 arp rosemary below its minimum temperature?

It tolerates winter lows to about −10 to −5 °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.