Several subspecies are recognized:Hairy vetch is very similar to tufted vetch (Vicia cracca), the most noticeable difference being that tufted vetch has a smooth stem.Vicia villosa, known as the hairy vetch, fodder vetch or winter vetch, is a plant native to Europe and western Asia. It is a legume, grown as a forage crop.
Hairy vetch is widely used by organic growers in the United States as a winter cover crop and in no-till farming, as it is both winter hardy and can fix as much as 200 lb/acre of atmospheric nitrogen. Disadvantages of hairy vetch in production agriculture are related to the crop having a portion of hard seed and its tendency to shatter seed early in the season - leading to it remaining in the field as a weed later in the season. This can be a particular problem in wheat production.
Organic gardeners often plant hairy vetch (a nitrogen-fixing legume) as a companion plant to tomatoes, as an alternative to rotating crops in small growing areas. When it is time to plant tomatoes in the spring, the hairy vetch is cut to the ground and the tomato seedlings are planted in holes dug through the matted residue and stubble. The vetch vegetation provides both nitrogen and an instant mulch that preserves moisture and keeps weeds from sprouting.