This plant is a member of the pea family. Flowers have both male and female organs.
It prefers sandy soil that is well drained, moist and acidic. But clearly it is not too picky since it easily grows wild through most of the country.
It has a symbiotic relationship with soil bacteria which form nodules on the roots of the sweetvetch and fix nitrogen.
Sow in fall, pre soak the seeds to help germination.