Published on Wednesday, 30 November -0001 00:00
With the increased interest in environmental issues, homeowners are becoming even more cautious of using pesticides in and around their homes. Because of its visibility, application of herbicides for weed control in the home lawn is often a concern. This concern brings an increased interest in natural products that are perceived as being safer than traditional synthetic products. Corn gluten meal may be the answer for homeowners that are searching for a natural way to control crabgrass and other annual weeds in the lawn. Corn gluten meal is a natural non-toxic substitute for synthetic pre-emergence herbicides. Corn gluten meal is a by-product of commercial corn milling that contains the protein fraction of the corn and poses no health risk to people or animals. Because it contains 10 percent nitrogen by weight, corn gluten meal doubles as a slow-release organic fertilizer. By applying corn gluten meal at the recommended rate twice a year, you are giving your lawn a total of four pounds of nitrogen annually, which is sufficient for your lawn's needs. Recent research has shown that a third application of corn gluten meal made in October produced very good spring green-up. It is important to note that corn gluten meal is a pre-emergence product only and does not kill existing plants. Annual weeds that are already up and growing will not be killed and the weeds will actually benefit from the nitrogen in the corn gluten meal. However, most of the seeds they produce later in the season shouldn't sprout if corn gluten meal has been properly applied. Likewise, existing perennial weeds like quackgrass, plantain, and dandelions will not be affected and will continue to come back from one year to the next because their roots survive most winters. What corn gluten meal will do is prevent the seeds that these weeds shed each year from sprouting so the population of perennial weeds, particularly plantain and dandelions, will decrease. Don't expect to see instant results from using corn gluten meal. Every year you properly apply corn gluten meal should give you better results and by the fourth year, weed control should be good. The action of corn gluten meal will be enhanced by increased mowing height. In experimental plots, grass mowed at a 3-inch mowing height had significantly fewer dandelions present than in plots that were mowed to a lower 1.5-inch mowing height. Corn gluten meal is available in powdered and pelletized forms, both of which work equally well. Apply corn gluten meal in early May, again in mid-August and probably again in mid-October. Spread the product evenly at the rate of twenty pounds per 1,000 square feet of lawn. Water it lightly into the soil to activate it. The August application is important because weeds like dandelions and chickweed produce seeds that sprout in the fall, their roots live over winter, and they have a head start the following spring. A third application in October will promote earlier green-up and better color of the lawn in the spring. Corn gluten meal can also be used safely in gardens to keep weed seeds from sprouting around perennial plants. It can also be used around bedding and vegetable transplants after they have been in the soil long enough to have become established. Wait until seedlings are up and growing well before applying corn gluten meal to flower or vegetable gardens where the seeds have been sown directly in the soil. Remember that corn gluten meal is non-selective and will stop nearly all seeds from germinating. A potential problem with corn gluten meal is that extensive moisture and soil microbial activity can reduce its effectiveness. You can control the amount of water you apply right after applying the corn gluten meal, but you cannot control rainfall. If it does not rain within five days of application, water it in with about a quarter inch of water. If it is too wet while the weed seeds are germinating, the seedlings may recover and form a root. Price and availability may also be a drawback. While it is becoming more readily available, corn gluten meal is still significantly more costly compared to synthetic pre-emergence herbicides. If you have a large lawn that requires a large amount of corn gluten meal, try calling local feed mills to find a source of corn gluten meal in bulk. Although it acts more slowly than synthetic pre-emergence herbicides and may be somewhat more costly, it is an organic way to control crabgrass and other pesky weeds in lawns.