Cold hardiness & minimum temperature

Is Walker's Low Catmint (Nepeta racemosa 'Walker's Low')cold hardy? Hardiness zone & min temp

Also called Walker's Low catmint, dwarf catmint.

More about walker's low catmint

About Walker's Low Catmint

Nepeta racemosa 'Walker's Low' · also called Walker's Low catmint, dwarf catmint · flowering

Despite its name, Walker's Low is a medium-sized catmint forming a dense mound of small grey-green leaves topped by clouds of lavender-blue flowers from late spring to autumn. A Perennial Plant of the Year winner, it is exceptionally floriferous, drought-hardy and bee-friendly. Shearing after the first flush keeps it tidy and triggers months of repeat bloom.

Cold limit: USDA 4-8 (fully hardy perennial outdoors) · RHS H7 (15-27°C)

Watch for — Root and crown rot: Wilting and yellowing in heavy, wet soil. Provide sharp drainage and never allow the crown to stand in water, especially over winter.

What walker's low catmint's hardiness rating actually means

Yes — walker's low catmint is genuinely cold hardy. Rated RHS H7 and USDA 4-8 (fully hardy perennial outdoors), 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 4-8 (fully hardy perennial outdoors) — 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. Walker's Low Catmint is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for walker's low catmint 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 walker's low catmint go outside or overwinter — and where?

Plant it out within USDA 4-8 (fully hardy perennial outdoors) 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 walker's low catmint can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H7 figure above.

Walker's Low Catmint hardiness — frequently asked questions

Is walker's low catmint cold hardy?

Yes — walker's low catmint is genuinely cold hardy. Rated RHS H7 and USDA 4-8 (fully hardy perennial outdoors), it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Walker's Low Catmint is hardy across USDA 4-8 (fully hardy perennial outdoors); 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 walker's low catmint can survive?

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

What hardiness zone is walker's low catmint?

Walker's Low Catmint is rated USDA 4-8 (fully hardy perennial outdoors) and RHS H7 — Hardy in the severest European continental winters.

Can walker's low catmint survive winter outside?

Plant it out within USDA 4-8 (fully hardy perennial outdoors) 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 walker's low catmint 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.