Does corn gluten meal kill weeds?
Yes. This natural byproduct of the wet-milling process of corn represents a big step in the continuing effort by scientists to find alternatives to synthetic pesticides. The development began in 1986 when researchers at Iowa State University were studying the effects of Pythium (fungus disease organism) on the growth of grass.

Corn gluten meal is used in cattle and poultry feed and in fish and dog food. It is a sixty-percent corn protein material that contains ten-percent nitrogen. Though produced as a fine, yellow powder, it can be pelletized for easier application to the soil. It offers pre-emergent control of weeds like dandelions, pigweed, crabgrass, plantain, lambs quarters, and curly dock.

Timing, as mentioned previously, is important. The corn gluten meal must be applied before the seed of the target weeds emerges above the soil. "The application should be made close to the time of weed germination. Moisture is necessary to activate the material, but extended wet periods can reduce its effectiveness," warns Dr. Christians. While the lawn is the prime site for many weeds, corn gluten meal can be used in flowerbeds and vegetable plots.

Because the product contains nitrogen, it also acts as an excellent fertilizer to plants that have gone beyond the germination stage. "Later work has repeatedly shown that corn gluten meal compares to the best commercially available natural fertilizers," says Dr. Christians. The current recommended rate of application is 20 pounds of product per 1,000 square feet. At 10 percent nitrogen by weight, this equates to a nitrogen application of 2 pounds per 1,000 square feet. However, always read and follow application rates provided on the package labels.

You can purchase Corn Gluten Meal at Farmer Co-ops and some garden centers. I purchase mine at the Cenex Co-op in Oregon off Hwy 138 near Hwy 14.