Plant · P-093

Yellow Sweet Clover

Melilotus officinalis

Yellow Sweet Clover is a biennial legume that colonizes poor open ground on its own, fixing nitrogen and breaking up compacted subsoil with a deep taproot before dying after it sets seed in its second year. Its early flowers make it one of the biggest honey sources in North America, and it doubles as forage - but only fresh: the plant's coumarin turns toxic to cattle if it is cut for hay and allowed to spoil or mold. The same chemicals that let it choke out competing weeds work just as well against native plants, so it belongs on cultivated ground rather than a wild margin.