Cold hardiness & minimum temperature

Is Spiny Germander (Teucrium subspinosum)cold hardy? Hardiness zone & min temp

Also called Spiny Germander, Balearic Germander.

More about spiny germander

About Spiny Germander

Teucrium subspinosum · also called Spiny Germander, Balearic Germander · flowering

Teucrium subspinosum is a cushion-forming, spiny, evergreen shrublet endemic to the Balearic Islands (primarily Mallorca and Cabrera), where it grows on dry, stony limestone hillsides. Its twisted, white-woolly, spine-tipped stems bear small grey-green leaves and loose racemes of two-lipped, clear pink flowers in summer. It is one of the most ornamental compact germanders for rock gardens and scree beds, and demands full sun with near-perfect drainage. The plant is mildly toxic if ingested due to diterpene compounds typical of the genus.

Cold limit: USDA 8-10 · RHS H4 (-10 to 32°C)

Watch for — Winter rot in wet soils: Being an island Mediterranean endemic, this species is especially susceptible to crown and root rot in cold, wet UK winters; grow in a raised scree bed or alpine house in wet regions.

What spiny germander's hardiness rating actually means

Yes — spiny germander is genuinely cold hardy. Rated RHS H4 and USDA 8-10, 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 8-10 — 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. Spiny Germander is built for winter — once established it takes hard frost and snow in its stride.

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

Plant it out within USDA 8-10 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 spiny germander can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H4 figure above.

Spiny Germander hardiness — frequently asked questions

Is spiny germander cold hardy?

Yes — spiny germander is genuinely cold hardy. Rated RHS H4 and USDA 8-10, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Spiny Germander is hardy across USDA 8-10; 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 spiny germander can survive?

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

What hardiness zone is spiny germander?

Spiny Germander is rated USDA 8-10 and RHS H4 — Hardy in an average winter across much of the temperate world.

Can spiny germander survive winter outside?

Plant it out within USDA 8-10 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 spiny germander 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.