Corn gluten is a by-product of corn that kills germinating crab-grass and other weeds while adding nitrogen, a fertilizer, to lawns. It will not hurt established weeds or grass, and is an effective pre-emergent herbicide for crabgrass, barnyard grass, foxtails, dandelion, lambs quarter, pigweed, purslane, and smartweed. Best of all, since it is organic, you don't have to stay off the grass like you do with chemical weed killers.
Corn gluten is generally sold as a golden yellow meal or as light brown granules and works in a standard spreader. You can expect 50-60% control over weed seedlings the first year. Results improve with repeated use over time. Initial results may be disappointing, but stick with it and after several applications, corn gluten can achieve better than 80% effectiveness.
• Never apply to newly seeded lawns – corn gluten is a germination inhibiter.
• Apply with a spreader at the rate of 12 – 20 pounds per 1,000 square feet.
• Hot or extended rainy conditions may require additional applications.
Timing is critical
For corn gluten to be effective, it must be applied under certain circumstances:
• Apply in spring just as the forsythias begin to bloom. Once they're done blooming, it's too late for a spring application and the product will simply fertilize your weeds.
• Corn gluten should be applied right before a rain or else watered in with a hose or sprinkler. If it doesn't rain within five days of application, it needs to be watered in with 1/4 inch of water.
• A dry period of a day or two must immediately follow or the application will fail.
• Apply again in early fall, between mid-August and mid-September.
• Like the spring application, it must be watered (by rain or hose).
• A dry period must follow.
Crab grass usually fills bare spots in the lawn. Some turf experts believe a bag of lawn grass is therefore more useful than corn gluten. They suggest that dense, healthy grass will naturally crowd out crabgrass, so growing more grass and filling in those thin areas and bare patches may result in minimized crabgrass pressure.
Check out our Products and Services for sources of corn gluten.