Cold hardiness & minimum temperature

Is Gold Dust Alyssum (Aurinia saxatilis)cold hardy? Hardiness zone & min temp

Also called Gold dust alyssum, Basket of gold, Yellow alyssum, Golden tuft.

More about gold dust alyssum

About Gold Dust Alyssum

Aurinia saxatilis · also called Gold dust alyssum, Basket of gold · flowering

Aurinia saxatilis is a mat-forming hardy perennial native to rocky limestone slopes and cliffs across central and southern Europe, producing dense clusters of vivid golden-yellow flowers in mid to late spring. It thrives in lean, sharply drained alkaline soil in full sun, tolerating drought and poor fertility far better than rich, moist conditions. The most critical care point is that this plant will quickly rot in heavy, moisture-retentive soil — good drainage is non-negotiable. It is not listed as toxic to cats or dogs by the ASPCA.

Cold limit: USDA 3-7 · RHS H6 (-20–30°C)

What gold dust alyssum's hardiness rating actually means

Yes — gold dust alyssum is genuinely cold hardy. Rated RHS H6 and USDA 3-7, 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 3-7 — 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. Gold Dust Alyssum is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for gold dust alyssum 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 gold dust alyssum go outside or overwinter — and where?

Plant it out within USDA 3-7 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 gold dust alyssum can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H6 figure above.

Gold Dust Alyssum hardiness — frequently asked questions

Is gold dust alyssum cold hardy?

Yes — gold dust alyssum is genuinely cold hardy. Rated RHS H6 and USDA 3-7, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Gold Dust Alyssum is hardy across USDA 3-7; 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 gold dust alyssum can survive?

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

What hardiness zone is gold dust alyssum?

Gold Dust Alyssum is rated USDA 3-7 and RHS H6 — Hardy throughout the UK and northern Europe.

Can gold dust alyssum survive winter outside?

Plant it out within USDA 3-7 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 gold dust alyssum 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.