Weeds are a problem faced by everyone who enjoys gardening. When we carefully prepare the soil to make a good home for our garden plants, we’re also creating ideal conditions for weeds to thrive.
Weeds not only detract from the beauty of our gardens, but they also compete for the water and nutrition that is meant to be used by the more desirable plants.
So what’s a gardener to do about weeds? We can smother existing weeds when creating new planting beds, but despite our best efforts, weed seeds will always be blowing into the beds. When those weed seeds germinate and grow, the weeds will once again make themselves right at home in the garden.
Now there’s a natural product available that helps prevent weed seeds from growing in the garden, and surprisingly, it is made from corn.
Corn gluten is a byproduct of the wet-milling process and has traditionally been used in cattle and poultry feed and also as an ingredient in dog food. It was discovered entirely by accident that corn gluten can also be used to prevent weed seeds from germinating. Not only can it suppress weeds, but it will also help feed your garden plants since it is also a source of nitrogen. And corn gluten won’t harm pets, people, birds or insects, making it very safe to use.
Corn gluten works by preventing germinated seeds from growing a root. A plant that has already grown roots will not be affected by corn gluten. For the best results, the corn gluten should be applied early in the season, before the weed seeds germinate and grow roots. As a pre-emergent herbicide, corn gluten tends to have a cumulative effect and becomes even more effective on weed seeds with repeated applications over time. One application of corn gluten continues to suppress weeds for 4-6 weeks, a bit less if the weather is unusually rainy or hot.
Corn gluten is typically applied by broadcasting it on the growing bed at a rate of 20-40 pounds per 1000 square feet. It may then be lightly raked into just the surface of the soil and watered in. Corn gluten will not be effective unless it is wetted and should be given a gentle shower after being applied. However, if there is a long rainy period after the corn gluten has been applied, it may lose its effectiveness. As with any herbicide, it can wash away, and weed seedlings may even recover and begin again to form roots if the soil surface remains wet for an extended time. Keep an eye on the weather and apply the corn gluten when no rain is expected for a few days. Always follow the instructions on the package when applying any herbicide or fertilizer.
Corn gluten will not harm mature plants and can be safely used in an existing flowerbed, vegetable garden or potted plants. Vegetable or flower seeds that are planted deeply, such as peas, corn or beans, won’t be affected by the corn gluten. But avoid using corn gluten where shallow-seeded plants such as lettuce or carrots will be grown. The corn gluten won’t have an effect on deeply planted seeds, but it will inhibit root growth in seeds that are planted close to the surface.
Corn gluten is sold under several brand names. Look for corn gluten herbicides at your local garden center or in the organic section of gardening catalogs. With a good dose of corn gluten on the garden, you can enjoy the garden more and spend less time pulling weeds
More Reading ResourcesPrinciples of Weed Control in California
Authors : Michael McGroarty