Cold hardiness & minimum temperature

Is Spearmint (Mentha spicata)cold hardy? Hardiness zone & min temp

Also called Garden Mint, Common Mint.

More about spearmint

About Spearmint

Mentha spicata · also called Garden Mint, Common Mint · herb

Spearmint is a hardy, vigorous perennial herb grown for its sweet, menthol-light leaves used in cooking, drinks and tea. It spreads aggressively by underground runners, so most gardeners confine it to a pot or buried barrier. Easy and forgiving, it tolerates part shade and a wide range of soils, returning reliably year after year in temperate gardens.

Cold limit: USDA 3-11 (hardy herbaceous perennial) · RHS H7 (15-21°C (tolerates 5-30°C in growth))

What spearmint's hardiness rating actually means

Yes — spearmint is genuinely cold hardy. Rated RHS H7 and USDA 3-11 (hardy herbaceous perennial), it lives outdoors all year and needs winter cold rather than protection from it. Its RHS rating of H7 means: Hardy in the severest European continental winters. On the US scale that maps to USDA 3-11 (hardy herbaceous perennial) — 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 below about −20 °C. Spearmint is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for spearmint as it gets too cold:

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

Plant it out within USDA 3-11 (hardy herbaceous perennial) 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 spearmint can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H7 figure above.

Spearmint hardiness — frequently asked questions

Is spearmint cold hardy?

Yes — spearmint is genuinely cold hardy. Rated RHS H7 and USDA 3-11 (hardy herbaceous perennial), it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Spearmint is hardy across USDA 3-11 (hardy herbaceous perennial); 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 spearmint can survive?

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

What hardiness zone is spearmint?

Spearmint is rated USDA 3-11 (hardy herbaceous perennial) and RHS H7 — Hardy in the severest European continental winters.

Can spearmint survive winter outside?

Plant it out within USDA 3-11 (hardy herbaceous perennial) 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 spearmint below its minimum temperature?

It tolerates winter lows to about −20 °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.