Effect

• Corn gluten meal kills the seeds that turn into weeds, not the roots or plants themselves. It will not eliminate perennial weed roots that survive the winter.
  
  

Origin

• Commercial corn mills produce corn gluten meal as a byproduct. High in protein, this meal is often used as animal feed.
  
  

Application

• Homeowners should apply corn gluten meal in late April or early May, then again in August. According to the University of Minnesota Extension, on each 1,000 square feet of lawn, homeowners should apply 20 pounds of corn gluten meal (powdered or pelletized), then water the ground.
  
  

Results

• This natural herbicide works more slowly than synthetic herbicides, gradually killing off weeds over time. The presence of weeds should be significantly diminished within about four years, according to the University of Minnesota Extension.
  
  

Drawbacks

• Although natural, corn gluten meal does have its drawbacks as a herbicide. Heavy rainfall can reduce its effectiveness. Also, it is expensive when compared with other options.