Cold hardiness & minimum temperature

Is Raceme catmint (Nepeta racemosa)cold hardy? Hardiness zone & min temp

Also called Raceme catmint, Dwarf catmint.

More about raceme catmint

About Raceme catmint

Nepeta racemosa · also called Raceme catmint, Dwarf catmint · herb

A compact, aromatic perennial producing a profusion of small violet-blue flower spikes over grey-green foliage from late spring through summer, with a strong rebloom after cutting back. Highly drought-tolerant once established. Pet-safe and attractive to bees, butterflies, and cats. Ideal for sunny borders, edging, and gravel gardens.

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

Watch for — Crown rot in wet winters: The greatest risk is waterlogged soil in winter, particularly in heavy clay. Plant in raised beds or gritty, free-draining soil and avoid mulching over the crown. Good drainage is the single most important factor for longevity.

What raceme catmint's hardiness rating actually means

Yes — raceme 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. Raceme catmint is built for winter — once established it takes hard frost and snow in its stride.

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

Raceme catmint hardiness — frequently asked questions

Is raceme catmint cold hardy?

Yes — raceme 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. Raceme 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 raceme catmint can survive?

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

What hardiness zone is raceme catmint?

Raceme catmint is rated USDA 4-8 and RHS H6 — Hardy throughout the UK and northern Europe.

Can raceme 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 raceme 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.