Organic Weed Control with Corn Gluten

Posted by Katie Elzer-Peters
September 8th, 2008
Filed in Weed Control
Tags: corn gluten, fertilizer, herbicides, pesticides, Weed Control

Organic weed control is one of the most difficult aspects of organic gardening. Too much hand weeding, and you lose valuable topsoil to erosion. Certain organic weed control options such as vinegar, boiling water and burning weeds with a torch are difficult to implement in flower beds or around other plants. However, there is one option you may not have heard of – corn gluten meal.

Corn gluten meal is a waste product of corn from the wet processing method used to make corn syrup or cornstarch. Corn gluten meal is 60% protein and 10% nitrogen, by weight. Research at Iowa State University has determined that corn gluten is an effective preemergence herbicide, which means that it kills the weeds at the time of germination. The gluten does not affect mature plantings. This makes it ideal for weed control for lawns and established gardens. The nitrogen content of corn gluten meal also makes it a natural fertilizer.

How Corn Gluten Works as a Preemergence Herbicide

Corn gluten is best for preventing weeds from sprouting, or killing them immediately after they sprout. The corn gluten works as a weed killer because it inhibits plants from growing roots. A seed might sprout and grow a “shoot,” which is the top part of the plant, but it will not be able to grow a root, and thus will not be able to survive. Be aware that it harms or kills many other plant seeds as well, so if you plan to reseed your lawn, wait about six weeks before seeding.

For corn gluten to work well, it must be watered in, and then allowed to dry. Heavy rains can cause plants to recover from the treatment with gluten, grow a root and survive.

Application of Corn Gluten for Weed Control

For corn gluten to be most effective controlling weeds, it should be applied in the fall and the spring. There are cool season weeds and warm season weeds, and because corn gluten acts as a preemergence herbicide, it is important to apply it before weeds begin to sprout at the beginning of the season.

NOW is the time to apply corn gluten meal for fall weed control. As you begin to use corn gluten for weed control in your established planting areas, you will see better results with time. Weed control will reach maximum effectiveness after four years of application at the right time during the season. Each season, the amount of corn gluten you will need to apply will be lower. For the first several years of application, the recommended application rate is 20 lbs per 1000 sq. ft. of area.

Where to Find Corn Gluten Meal

Corn gluten weed control products are not available at every garden center or hardware store, but they are becoming more readily available.

As with all gardening ventures, using corn gluten for weed control is partially an exercise in patience. Research proves that it does work, and it is a much safer form of weed control for people, pets and the environment.

Condensed information and directions can be found at Pesticide.org.