Corn gluten is a byproduct of the corn milling process, which was originally used as a supplement in hog feed but is now a common organic alternative to synthetic chemical herbicides. It can be used as a pre-emergent herbicide to control crabgrass and other lawn weeds, and also has nutritional properties. Corn gluten is about 10% nitrogen by weight. This nitrogen is slowly released over a 3-4 month period.
Standard application rate is 20lbs of corn gluten per 1000 sq ft of lawn.