Cold hardiness & minimum temperature

Is Garden Catmint (Nepeta x faassenii)cold hardy? Hardiness zone & min temp

Also called garden catmint, Faassen's catmint.

More about garden catmint

About Garden Catmint

Nepeta x faassenii · also called garden catmint, Faassen's catmint · flowering

Garden catmint is a sterile, clump-forming perennial prized for soft grey-green aromatic foliage and long sprays of lavender-blue flowers from late spring into autumn. A magnet for bees and butterflies, it thrives in poor, free-draining soil and full sun, shrugging off heat and drought. Shearing spent flowers triggers a fresh, tidy second flush.

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

Watch for — Root and crown rot: Yellowing, collapsing crowns in wet or heavy soil. Plant in sharply drained ground and never let it sit waterlogged over winter.

What garden catmint's hardiness rating actually means

Yes — garden 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. Garden Catmint is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for garden 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 garden 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 garden catmint can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H7 figure above.

Garden Catmint hardiness — frequently asked questions

Is garden catmint cold hardy?

Yes — garden 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. Garden 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 garden catmint can survive?

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

What hardiness zone is garden catmint?

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

Can garden 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 garden 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.