Cold hardiness & minimum temperature

Is Black Medick (Medicago lupulina)cold hardy? Hardiness zone & min temp

Also called Black Medick, Black Medic, Hop Clover, Nonesuch, Yellow Trefoil.

More about black medick

About Black Medick

Medicago lupulina · also called Black Medick, Black Medic · flowering

Medicago lupulina is a low-growing annual or short-lived perennial legume native to grasslands, roadsides, and disturbed ground across Europe, Asia, and northern Africa, widely naturalised in North America and Australasia. It thrives in full sun on poor to moderately fertile, well-drained soils and, as a legume, fixes atmospheric nitrogen through root nodules — so avoid nitrogen-rich fertilisers. The tiny yellow clover-like flowers turn into distinctive black coiled seed pods that give the plant its common name. It is not considered toxic to cats or dogs.

Cold limit: USDA 3-10 · RHS H7 (-25 to 30°C)

What black medick's hardiness rating actually means

Yes — black medick is genuinely cold hardy. Rated RHS H7 and USDA 3-10, it lives outdoors all year and needs winter cold rather than protection from it. Its RHS rating of H7 means: Hardy in the severest European continental winters. On the US scale that maps to USDA 3-10 — 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 below about −20 °C. Black Medick is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for black medick as it gets too cold:

It tolerates winter lows to about −20 °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 black medick go outside or overwinter — and where?

Plant it out within USDA 3-10 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 black medick can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H7 figure above.

Black Medick hardiness — frequently asked questions

Is black medick cold hardy?

Yes — black medick is genuinely cold hardy. Rated RHS H7 and USDA 3-10, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Black Medick is hardy across USDA 3-10; 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 black medick can survive?

Minimum survivable temperature is roughly below about −20 °C. Black Medick is built for winter — once established it takes hard frost and snow in its stride.

What hardiness zone is black medick?

Black Medick is rated USDA 3-10 and RHS H7 — Hardy in the severest European continental winters.

Can black medick survive winter outside?

Plant it out within USDA 3-10 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 black medick below its minimum temperature?

It tolerates winter lows to about −20 °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.