Birdsfoot trefoil is a perennial legume that adapts well to production on poorly drained, low-pH soils. It can reseed itself, is resistant to Phytophthora root rot and numerous alfalfa insects, responds well to fertilization, and does not cause bloat in animals. As a result, it is being grown more often in the northern United States and southern Canada, where production of other forage legumes is limited.
Grown in well-drained, fertile soils, birdsfoot trefoil will not yield as well as alfalfa; yields usually are 50 to 80 percent that of alfalfa in these soils. Therefore, the site in which trefoil is to be grown should have limitations that make alfalfa production difficult.