Cold hardiness & minimum temperature

Is Nerved Catmint (Nepeta nervosa)cold hardy? Hardiness zone & min temp

Also called Nerved Catmint, Kashmir Catmint.

More about nerved catmint

About Nerved Catmint

Nepeta nervosa · also called Nerved Catmint, Kashmir Catmint · flowering

Nerved Catmint is a compact, bushy species from Kashmir producing dense spikes of bright blue to violet flowers through summer. It is distinct for its prominently veined, lance-shaped leaves compared to the soft grey foliage of most catmints. Ideal for rock gardens, raised beds, and front-of-border plantings in full sun with sharp drainage.

Cold limit: USDA 4–8 · RHS H6 (−20°C to 35°C)

Watch for — Crown rot in wet winters: The main vulnerability of this species. Ensure very sharp drainage and avoid mulching over the crown. In cold, wet climates, grow in a raised bed with grit incorporated into the soil.

What nerved catmint's hardiness rating actually means

Yes — nerved catmint 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. Nerved Catmint is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for nerved catmint 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 nerved catmint 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 nerved catmint can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H6 figure above.

Nerved Catmint hardiness — frequently asked questions

Is nerved catmint cold hardy?

Yes — nerved catmint 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. Nerved Catmint 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 nerved catmint can survive?

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

What hardiness zone is nerved catmint?

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

Can nerved catmint 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 nerved catmint 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.