Birdsfoot trefoil is a deep-rooted perennial forage legume that is especially well suited to the moderate to somewhat poorly drained soils of northern and western Pennsylvania. Although birdsfoot trefoil is not as productive as alfalfa on good alfalfa soils, its yields have exceeded those of alfalfa on wetter soils. It normally outlives red clover by several years. Trefoil also is bloat free; in fact, no case of bloat has ever been recorded in animals grazing on this legume.
Birdsfoot trefoil varieties are classified by growth habit into two types: Empire and European. Empire birdsfoot trefoils are better adapted for grazing since they have fine stems and a prostrate growth habit. European birdsfoot trefoils are better adapted for hay production since they have a more erect growth habit.