Cold hardiness & minimum temperature

Is Thessalian Aubrieta (Aubrieta thessala)cold hardy? Hardiness zone & min temp

Also called Thessalian aubrieta, Rock cress, False rock cress.

More about thessalian aubrieta

About Thessalian Aubrieta

Aubrieta thessala · also called Thessalian aubrieta, Rock cress · flowering

Aubrieta thessala is a mat-forming evergreen perennial native to rocky limestone habitats in Greece and the Balkans. It thrives in full sun with sharply drained, alkaline to neutral soil and is a classic choice for dry stone walls, rock gardens, and scree beds. The single most important care point is to trim the plant hard immediately after flowering to prevent it becoming leggy and to encourage a compact second flush of growth. Not listed by the ASPCA; considered non-toxic to pets by most horticultural sources, though confirm with a vet if ingestion is suspected.

Cold limit: USDA 4-8 · RHS H6 (-20°C to 25°C)

What thessalian aubrieta's hardiness rating actually means

Yes — thessalian aubrieta is genuinely cold hardy. Rated RHS H6 and USDA 4-8, 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 4-8 — 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. Thessalian Aubrieta is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for thessalian aubrieta 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 thessalian aubrieta go outside or overwinter — and where?

Plant it out within USDA 4-8 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 thessalian aubrieta can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H6 figure above.

Thessalian Aubrieta hardiness — frequently asked questions

Is thessalian aubrieta cold hardy?

Yes — thessalian aubrieta is genuinely cold hardy. Rated RHS H6 and USDA 4-8, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Thessalian Aubrieta is hardy across USDA 4-8; 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 thessalian aubrieta can survive?

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

What hardiness zone is thessalian aubrieta?

Thessalian Aubrieta is rated USDA 4-8 and RHS H6 — Hardy throughout the UK and northern Europe.

Can thessalian aubrieta survive winter outside?

Plant it out within USDA 4-8 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 thessalian aubrieta 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.