Cow vetch and hairy vetch (Vicia cracca and V. villosa)
 Native Substitutes:
 Control Methods  
Mechanical
Chemical
Biological
Pulling small infestations before seeds develop, to free native plants Spray with selective herbicide such as clopyralid (Transline) None

 

 
Appearance: Both plants are annual or short-lived perennial forbs. Their weak stems grow 2-3' high and clamber over other vegetation, smothering it. The stem of hairy vetch has spreading hairs. Leaves: Alternate, pinnately compound (leaflets on both sides of a common stalk); 8-12 pairs of narrow oval-shaped opposite leaflets. Flower: Violet-blue on cow vetch and blue and white on hairy vetch. Flowers are clustered on one-sided spikes and bloom from May to August. Seed: Seeds are contained in numerous inch-long pods. Pods of cow vetch are brownish lance-shaped and flat; pods of hairy vetch are gray to black and hairy. Root: Both plants have a 1-3' long taproot.
Cow vetch and hairy vetch are not a threat to healthy native prairies at this time, but can be a problem in prairie reconstructions and on disturbed sites. They grow best on dry sandy soils of disturbed fields and thickets. Both vetches are naturalized in the U.S. and are grown for forage, green fertilizer or cover crop. They occur throughout the eastern and Midwestern states extending into southern Canada .