Cold hardiness & minimum temperature

Is Arp Rosemary (Rosmarinus officinalis 'Arp')cold hardy? Hardiness zone & min temp

Also called Arp Rosemary, Hardy Rosemary.

More about arp rosemary

About Arp Rosemary

Rosmarinus officinalis 'Arp' · also called Arp Rosemary, Hardy Rosemary · herb

Arp Rosemary is one of the hardiest rosemary cultivars, valued for cold tolerance down to USDA Zone 6 and its strongly aromatic, gray-green needle foliage. It forms an upright, shrubby mound perfect for herb gardens and ornamental borders. Grow in full sun with excellent drainage; drought-tolerant once established.

Cold limit: USDA 6-11 · RHS H5 (-15 to 35°C)

What arp rosemary's hardiness rating actually means

Yes — arp rosemary is genuinely cold hardy. Rated RHS H5 and USDA 6-11, it lives outdoors all year and needs winter cold rather than protection from it. Its RHS rating of H5 means: Hardy in most of the UK and in cold winters. On the US scale that maps to USDA 6-11 — 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 −15 to −10 °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 −15 to −10 °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 6-11 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 H5 figure above.

Arp Rosemary hardiness — frequently asked questions

Is arp rosemary cold hardy?

Yes — arp rosemary is genuinely cold hardy. Rated RHS H5 and USDA 6-11, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Arp Rosemary is hardy across USDA 6-11; 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 −15 to −10 °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 6-11 and RHS H5 — Hardy in most of the UK and in cold winters.

Can arp rosemary survive winter outside?

Plant it out within USDA 6-11 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 −15 to −10 °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.