Cold hardiness & minimum temperature

Is Liquorice (Glycyrrhiza glabra)cold hardy? Hardiness zone & min temp

Also called Liquorice, Licorice, Sweet Root, Common Liquorice.

More about liquorice

About Liquorice

Glycyrrhiza glabra · also called Liquorice, Licorice · herb

Liquorice is a deep-rooted perennial legume native to the Mediterranean and southwestern Asia, cultivated for its thick, sweet taproot which contains glycyrrhizin — up to 50 times sweeter than sucrose. It requires a long, warm growing season, deep well-drained soil, and full sun. Roots are typically harvested after 3–4 years for culinary and medicinal use.

Cold limit: USDA 6–11 · RHS H5 (-15–35°C)

What liquorice's hardiness rating actually means

Yes — liquorice is genuinely cold hardy. Rated RHS H5 and USDA 6–11, 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 6–11 — 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. Liquorice is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for liquorice 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 liquorice go outside or overwinter — and where?

Plant it out within USDA 6–11 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 liquorice can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H5 figure above.

Liquorice hardiness — frequently asked questions

Is liquorice cold hardy?

Yes — liquorice is genuinely cold hardy. Rated RHS H5 and USDA 6–11, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Liquorice is hardy across USDA 6–11; 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 liquorice can survive?

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

What hardiness zone is liquorice?

Liquorice is rated USDA 6–11 and RHS H5 — Hardy in most of the UK and in cold winters.

Can liquorice survive winter outside?

Plant it out within USDA 6–11 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 liquorice 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.