Cold hardiness & minimum temperature

Is Golden Lemon Thyme (Thymus citriodorus 'Aureus')cold hardy? Hardiness zone & min temp

Also called Golden Lemon Thyme, Lemon Thyme 'Aureus'.

More about golden lemon thyme

About Golden Lemon Thyme

Thymus citriodorus 'Aureus' · also called Golden Lemon Thyme, Lemon Thyme 'Aureus' · herb

Golden Lemon Thyme is an ornamental-culinary hybrid thyme with bright gold-edged leaves and a distinctive citrus-lemon scent. It forms a low, spreading mound and produces pale lilac flowers in summer. Used fresh in salads, poultry, and fish dishes, it needs full sun to maintain its golden variegation and flavour.

Cold limit: USDA 6–9 · RHS H5 (-10–30°C)

Watch for — Root rot in wet soil: Soggy or compacted soil causes rapid crown rot, especially in winter. Ensure sharp drainage and, in containers, use a terracotta pot with drainage holes. Never let roots sit in standing water.

What golden lemon thyme's hardiness rating actually means

Yes — golden lemon thyme is genuinely cold hardy. Rated RHS H5 and USDA 6–9, it lives outdoors all year and needs winter cold rather than protection from it. Its RHS rating of H5 means: Hardy in most of the UK and in cold winters. On the US scale that maps to USDA 6–9 — 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 −15 to −10 °C. Golden Lemon Thyme is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for golden lemon thyme as it gets too cold:

It tolerates winter lows to about −15 to −10 °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 golden lemon thyme go outside or overwinter — and where?

Plant it out within USDA 6–9 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 golden lemon thyme can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H5 figure above.

Golden Lemon Thyme hardiness — frequently asked questions

Is golden lemon thyme cold hardy?

Yes — golden lemon thyme is genuinely cold hardy. Rated RHS H5 and USDA 6–9, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Golden Lemon Thyme is hardy across USDA 6–9; 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 golden lemon thyme can survive?

Minimum survivable temperature is roughly about −15 to −10 °C. Golden Lemon Thyme is built for winter — once established it takes hard frost and snow in its stride.

What hardiness zone is golden lemon thyme?

Golden Lemon Thyme is rated USDA 6–9 and RHS H5 — Hardy in most of the UK and in cold winters.

Can golden lemon thyme survive winter outside?

Plant it out within USDA 6–9 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 golden lemon thyme below its minimum temperature?

It tolerates winter lows to about −15 to −10 °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.