Grass Size

• Barnyard grass grows to heights of up to 5 feet under ideal conditions. Flat leaves form from the stem of the grass and are smooth on the upper surface of the leaf. Immature barnyard grass may form a stem parallel to the ground that becomes upright as the plant matures.
  
  

Blooms

• Blooms form in the summer or early fall, depending on local weather conditions. The blooms form on the stem that can extend as much as 10 inches. Individual flowers are small, with flowers drooping from the head.
  
  

Seeds

• Seeds form on barnyard grass after flowering and drop to the ground in the fall of the year. The seeds germinate the next spring when soil temperatures are about 60 degrees Fahrenheit. The same conditions that prompt the growth of crabgrass are also favorable to barnyard grass. The two wild grasses often pose problems to homeowners and turf grass groundskeepers.
  
  

Control

• The same control methods for crabgrass work to control barnyard grass. Pre-emergent herbicides applied before the seeds germinate or post-emergent herbicides that kill weeds that are already growing can be used. Preventing barnyard grass from going to seed by cultivation, mowing or chemical control eliminates the seeds that become the next generation of plants.