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A picture of a Yellow Trefoil

Yellow Trefoil

Medicago lupulina

Also known as

Black Medick, Nonesuch, Hop Clover, Black Clover

Medicago lupulina inflorescence, hopklaver bloeiwijze by Rasbak (CC BY-SA 3.0)

Partial Shade
Easy care
Moderate watering
Frost Hardy


RHS hardiness


Minimum temperature

Expected size








2 years to reach maturity


  • spring
  • summer
  • autumn
  • winter

This plant has a mild fragrance

More images of Yellow Trefoil

A close up of a flower
A close up of a garden
A close up of a flower

Yellow Trefoil Overview

Medicago lupulina is a pretty summer wildflower that can be found growing in fields and pastures as well as disturbed areas in gardens and lawns. It produces trifoliate leaves around a central stem and in summer a cluster of yellow flowers that develop into black seed pods. Commonly known as Black Clover, Black Medic, Hop Clover and Yellow Trefoil, it spreads out low to the ground only getting to between 15 cm (6") to 80 cm (31") in height. Medicago lupulina thrives in poor soil conditions, but as member of the legume family, its roots contain nitrogen-fixing nodules which over time will improve the soil.

Common problems with Yellow Trefoil

Generally pest and disease free

    How to harvest Yellow Trefoil

    Collect seed when ripe

    How to propagate Yellow Trefoil


    Sow seed in situ, germination should occur within a few weeks.


    Propagate from seeds or cuttings.

    Special features of Yellow Trefoil

    Crop rotation

    Used as a green manure, this plant will increase nitrogen levels in the soil for following crops.

    Attracts useful insects

    A popular food source for bees, it will attract a range of pollinating insects.

    Other uses of Yellow Trefoil

    Suitable for coastal conditions.

    Animal fodder

    Can be grown in poor soils as pasture for sheep to graze on.

    Green manure

    Grow to capture and release nitrogen into the soil. Dig back into the top 15 cm (6") before the flowers develop.