Q. I have seen corn gluten meal sold as a pre-emergent herbicide. What can you tell me about it?

A. Corn gluten meal (CGM) is sold as a natural pre-emergent herbicide and fertilizer. CGM contains naturally occurring chemicals that suppress the growth of grasses and broadleaf weeds during germination. If you are reseeding your lawn, do not apply CGM, since it will inhibit the germination of your grass seeds. Since it contains approximately ten percent nitrogen, it also has an added benefit of fertilizing your lawn at the same time as inhibiting weed seed germination. The rate of application as well as the timing are critical for maximum effectiveness. CGM should be applied before weed seeds germinate in the spring—approximately late March to early April—followed by another application in late summer—approximately late August to early September. Make sure to follow label directions carefully. 

Please contact Plant Information Service at (847) 835-0972 or Click here to show mail address for more detailed information.