Cold hardiness & minimum temperature

Is Turkish Catmint (Nepeta phyllochlamys)cold hardy? Hardiness zone & min temp

Also called Turkish Catmint.

More about turkish catmint

About Turkish Catmint

Nepeta phyllochlamys · also called Turkish Catmint · flowering

Turkish Catmint is a rare, compact species endemic to a small area of northwestern Turkey. It forms low, silver-grey mounds of woolly, aromatic foliage topped with pale lavender-blue flowers in summer. Well-suited to rock gardens, raised beds, and gravel plantings, it demands perfect drainage and full sun, and is intolerant of winter wet.

Cold limit: USDA 7–9 · RHS H4 (-5–28°C)

Watch for — Crown rot from winter wet: The most common cause of plant death in cool, humid climates. Protect with a pane of glass or move containers under cover from late autumn to early spring. A collar of grit around the crown helps deflect moisture.

What turkish catmint's hardiness rating actually means

Yes — turkish catmint is genuinely cold hardy. Rated RHS H4 and USDA 7–9, it lives outdoors all year and needs winter cold rather than protection from it. Its RHS rating of H4 means: Hardy in an average winter across much of the temperate world. On the US scale that maps to USDA 7–9 — 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 −10 to −5 °C. Turkish Catmint is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for turkish catmint as it gets too cold:

It tolerates winter lows to about −10 to −5 °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 turkish catmint go outside or overwinter — and where?

Plant it out within USDA 7–9 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 turkish catmint can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H4 figure above.

Turkish Catmint hardiness — frequently asked questions

Is turkish catmint cold hardy?

Yes — turkish catmint is genuinely cold hardy. Rated RHS H4 and USDA 7–9, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Turkish Catmint is hardy across USDA 7–9; 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 turkish catmint can survive?

Minimum survivable temperature is roughly about −10 to −5 °C. Turkish Catmint is built for winter — once established it takes hard frost and snow in its stride.

What hardiness zone is turkish catmint?

Turkish Catmint is rated USDA 7–9 and RHS H4 — Hardy in an average winter across much of the temperate world.

Can turkish catmint survive winter outside?

Plant it out within USDA 7–9 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 turkish catmint below its minimum temperature?

It tolerates winter lows to about −10 to −5 °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.