Cold hardiness & minimum temperature

Is Camphor Catmint (Nepeta camphorata)cold hardy? Hardiness zone & min temp

Also called Camphor Catmint, Camphor-Scented Catmint.

More about camphor catmint

About Camphor Catmint

Nepeta camphorata · also called Camphor Catmint, Camphor-Scented Catmint · herb

Camphor Catmint is a strongly aromatic Mediterranean perennial with square stems, grey-green leaves, and small white flowers marked with purple dots. Its distinctive camphor-heavy scent differs from typical catmints. Hardy and drought-tolerant once established, it suits dry herb gardens, gravel plantings, and rock garden edges where drainage is good and sun is plentiful.

Cold limit: USDA 6–9 · RHS H5 (-10–28°C)

Watch for — Root rot in heavy, wet soils: Heavy clay combined with winter wet causes crown and root rot. Improve drainage before planting by incorporating coarse grit. In containers, use a gritty, well-drained compost mix and ensure drainage holes are clear.

What camphor catmint's hardiness rating actually means

Yes — camphor catmint is genuinely cold hardy. Rated RHS H5 and USDA 6–9, 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 6–9 — 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. Camphor Catmint is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for camphor catmint 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 camphor catmint go outside or overwinter — and where?

Plant it out within USDA 6–9 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 camphor catmint can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H5 figure above.

Camphor Catmint hardiness — frequently asked questions

Is camphor catmint cold hardy?

Yes — camphor catmint is genuinely cold hardy. Rated RHS H5 and USDA 6–9, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Camphor Catmint is hardy across USDA 6–9; 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 camphor catmint can survive?

Minimum survivable temperature is roughly about −15 to −10 °C. Camphor Catmint is built for winter — once established it takes hard frost and snow in its stride.

What hardiness zone is camphor catmint?

Camphor Catmint is rated USDA 6–9 and RHS H5 — Hardy in most of the UK and in cold winters.

Can camphor catmint survive winter outside?

Plant it out within USDA 6–9 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 camphor catmint 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.