Cold hardiness & minimum temperature

Is Mountain Germander (Teucrium montanum)cold hardy? Hardiness zone & min temp

Also called Mountain Germander, Creeping Germander.

More about mountain germander

About Mountain Germander

Teucrium montanum · also called Mountain Germander, Creeping Germander · flowering

Teucrium montanum is a low, mat-forming evergreen subshrub native to calcareous rocky hillsides and limestone grasslands across central and southern Europe, from the Iberian Peninsula to the Balkans. It bears narrow, grey-green aromatic leaves and produces creamy-white to pale yellow flowers on short terminal heads from June to September, attracting bees and butterflies. Full sun and sharply drained, alkaline soil are essential; it excels in rock gardens and dry-stone wall crevices. The plant is mildly toxic if ingested due to diterpene compounds present throughout the Teucrium genus.

Cold limit: USDA 5-9 · RHS H6 (-20 to 28°C)

Watch for — Crown rot in wet winters: The primary threat; perfect drainage — ideally in a raised rock garden or scree bed — is the best preventive measure, as no amount of treatment reverses crown rot once established.

What mountain germander's hardiness rating actually means

Yes — mountain germander is genuinely cold hardy. Rated RHS H6 and USDA 5-9, 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 5-9 — 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 −20 to −15 °C. Mountain Germander is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for mountain germander 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 mountain germander go outside or overwinter — and where?

Plant it out within USDA 5-9 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 mountain germander can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H6 figure above.

Mountain Germander hardiness — frequently asked questions

Is mountain germander cold hardy?

Yes — mountain germander is genuinely cold hardy. Rated RHS H6 and USDA 5-9, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Mountain Germander is hardy across USDA 5-9; 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 mountain germander can survive?

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

What hardiness zone is mountain germander?

Mountain Germander is rated USDA 5-9 and RHS H6 — Hardy throughout the UK and northern Europe.

Can mountain germander survive winter outside?

Plant it out within USDA 5-9 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 mountain germander 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.