Abstract
Alfalfa is the world's most important forage crop, and the western U.S. is its most important production area. Feral alfalfa is common and can potentially lower the genetic purity of alfalfa seed and cultivated fields. For conventional and organic alfalfa growers concerned about the integrity of their crops, this publication describes occurrences of feral alfalfa, discusses how genetic traits spread and suggests stewardship practices to minimize effects.