Corn meal for weeds

Cornmeal As Weed Killer And Pest Control: How To Use Cornmeal Gluten In The Garden

Cornmeal gluten, commonly referred to as corn gluten meal (CGM), is the by-product of corn wet milling. It is used to feed cattle, fish, dogs, and poultry. Gluten meal is known as a natural substitute for chemical pre-emergent herbicides. Using this cornmeal as weed killer is a great way to eradicate weeds without the threat of toxic chemicals. If you have pets or small children, gluten meal is a great option.

Gluten Cornmeal as Weed Killer

Researchers at Iowa State University discovered by accident that cornmeal gluten acts as an herbicide while they were doing disease research. They saw that corn gluten meal kept grass and other seeds, such as crabgrass, dandelions and chickweed, from sprouting.

It is important to note that cornmeal gluten is only effective against seeds, not plants that are mature and is most effective with corn gluten having at least 60% proteins in it. For annual weeds that are growing, plain cornmeal products will not kill it. These weeds include:

  • foxtail
  • purslane
  • pigweed
  • crabgrass

Perennial weeds will not be damaged either. They pop back up year after year because their roots survive under the soil over winter. Some of these include:

  • dandelions
  • quack grass
  • plantain

However, cornmeal gluten will stop the seeds that these weeds shed in the summer so that the weeds will not increase. With consistent use of gluten meal products, these weeds will gradually decline.

How to Use Cornmeal Gluten in the Garden

Many people use corn gluten on their lawns, but it can be safely and effectively used in gardens as well. Using gluten cornmeal in gardens is a great way to keep weed seeds from sprouting and will not damage existing plants, shrubs or trees.

Be sure to follow the application instructions on the package and apply before weeds start to grow. Sometimes this can be a very tight window but is best done in early spring. Be sure to wait to apply in flower and vegetable beds where seeds are sown at least until the seeds are grown up a bit. If applied too early, it can prevent these seeds from sprouting.

Using Cornmeal Gluten to Kill Ants

Cornmeal gluten is also a popular method to control ants. Pouring it wherever you see ants traveling is the best option. They will pick up the gluten and take it to the nest where they will feed on it. Because the ants cannot digest this cornmeal product, they will starve to death. It may take up to a week or so before you see your ant population dwindling.

Tip: If you have large areas to cover, you can try a spray form for ease of application. Apply every four weeks, or after heavy rains, during the growing season to maintain effectiveness.

Corn gluten meal did not prevent weeds from germinating in OSU study

“I’ve seen nursery situations where the applied product caused a bad odor, as do some herbicides, and attracted rodents,” said Altland. “In nursery situations where the goal is complete weed suppression, my overall impression is that it doesn’t work that well.”

“My overall impression has been that in turfgrass it provides a lot of nitrogen,” added Altland. “Thicker, denser turf from high nitrogen rates will reduce weed numbers alone, without the help of herbicides.

“Applying 20 pounds per 1,000 square feet of corn gluten meal would be equivalent to two pounds of nitrogen per 1,000 square feet. That’s a lot of nitrogen! Applying that much nitrogen is not good for the environment. It doesn’t matter if it’s a ‘natural’ fertilizer or not. That nitrogen will ultimately be converted to nitrates, which potentially could leach into groundwater.”

It is not clear why the commercial version of corn gluten meal used in OSU trials was not effective, said Cook. One possibility is that the product as formulated for sale has a short shelf life and loses potency during manufacture, shipping and storage. Further research needs to be done to test this hypothesis, he said.

If you want to discourage weeds from germinating and growing in your garden beds over the winter, try adding mulch to soil surfaces. Use a minimum of three to six inches of composted material. Tuck mulch up to the shoulders of your perennials, but don’t cover the growing crown until freezing cold weather sets in. If you cover plant crowns too soon, they may begin to grow under the mulch and could be killed when temperatures dip.

Shredded bark, leaves, mint hay, wood chips, or yard waste all offer benefits. Large chunky material such as fresh clean wood chips and bark nuggets work best for weed control, as they are low in available nutrients so won’t fertilize germinating weeds.

Avoid mulching with hay or with ryegrass straw. Their seeds will sprout to create an unnecessary headache for you in the spring. And don’t use grass clippings from a lawn treated with a weed-and-feed preparation. The herbicide in the clippings can damage your shrubs.

A low-nutrient mulch such as well-rotted sawdust will benefit shrubs such as roses, azaleas, rhododendrons and hydrangeas. Lilies, dahlias and spring bulbs will do better with this type of mulching also. But be aware that composted sawdust or other fine organic material may contribute to weed growth.

Caneberries benefit from higher-nutrient mulches such as composted manure. Dormant vegetable beds can use a six-inch blanket of manure and leaves. Rhubarb and asparagus beds do best covered with a mix of well-composted straw and manure.

Over the winter, the composted material will mix with the soil, so a second application of mulch in March or April will keep your garden soil in better condition.

In 2015, research from Washington State University further disputed the findings that corn gluten meal was as effective as widely believed :

The principal researcher and patent-holder of CGM, Dr. Nick Christians, is cautious in his recommendation of CGM for weed control. He and his students and staff have published a number of papers in the scientific and popular literature. These researchers are careful to point out that CGM does not affect existing weeds, and that the nitrogen in CGM will benefit existing weeds as well as desirable plants. Therefore, inadequate weed removal prior to treatment can actually result in an increased weed problem.

CGM is not a selective product, nor is it effective on all weed types. Several species of weeds, flowers, and vegetables are inhibited by CGM, while others are not. Effectiveness in greenhouse trials generally increases with application rate (as does the cost).

Rumors about cornmeal as a weed killer or antifungal substance have apparently spread since at least 2010, when horticultural expert Dr. Linda Chalker-Scott debunked the rumors of its efficacy as baseless.

Claims that cornmeal is an effective weed inhibitor have been circulating for at least a decade. In 1991, Iowa State University patented corn gluten meal as a weed inhibitor, but cornmeal and CGM are not the same thing . Furthermore, the the efficacy of CGM has been disputed as well.


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Cornmeal adds a specific flavor and texture to recipes and has many uses outside of the kitchen as well. Learn more with these 5 Uses for Cornmeal.

Have you ever thought about the many uses of cornmeal? Cornmeal is a course flour made from dried corn. It is a common staple food, but most of us forget all about it. However, cornmeal makes for amazing recipes. It adds texture and gives you a better taste all around. Here are 5 Uses for Cornmeal in and out of the kitchen.

5 Uses for Cornmeal

1. Coat Your Favorite Foods

Cornmeal is a staple in homes that deep fry many of their favorite foods. This is because cornmeal makes the perfect coating for fried foods such as fish, chicken, fried green tomatoes and other infamous fried foods. It gives the perfect amount of crunch and texture to your deep-fried foods. I like to mix my cornmeal with garlic salt, pepper, and garlic powder to give it a nice kick when using it as a coating.

2. Muffins

Instead of using flour in your muffin mix, you can use cornmeal. Cornmeal gives your muffins a little extra texture and adds to the flavor. Since cornmeal already has a flavor, you will want to make muffins that go well with that flavor. Here are a few great recipes:

  • Cornmeal Muffins: Just like cornbread jiffy mix except homemade! Add ¼ cup of sugar for a sweeter taste.
  • Honey Cornbread muffins: If you have ever added honey to your cornbread, you know this is a sweet treat.
  • Cranberry Cornmeal muffins: Betty Crocker knows how good cornmeal muffins are, and you should too.

3. Exfoliating Mask

Cornmeal isn’t only for food. In fact, unlike harmful facial products at the store, cornmeal can be used as a natural exfoliating mask. Simply mix 5 tablespoons of cornmeal, 1 egg, and a pinch of salt in a bowl. Once all the ingredients are mixed, thoroughly, apply to your face by massaging it in with your fingertips. Rinse immediately, or leave it on as a mask for 5-minutes.

4. Homemade Deodorant

Did you know that cornstarch (a cornmeal variety) is an ingredient in most antiperspirants? The thin cornstarch can be applied under sweaty armpits and in shoes to help absorb the moisture. You might not get the fresh fruity smell, but adding a few drops of essential oils can help with that.

5. Natural Abrasive

Since cornmeal is course, naturally, it is a great tool to getting stuck food off pots and pans. Simply add a little cornmeal to your dirty dishes and start scrubbing it. The sandpaper effect will crack through all that stuck on food making dishwashing a breeze.

What other ways have you found to use cornmeal? Share your cornmeal uses in the comments below!

More Ways to Use Common Food Ingredients:

20 Frugal Ways to Use Coconut Oil

10 Handy Uses for Cream of Tartar

20 Frugal Household Uses for Lemons

20 Frugal Ways to Use Salt

10 Unusual Uses for Cinnamon


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My cupboards are full of half-bags. A half bag of hazelnut flour from when I made linzer cookies, maybe a quarter bag of chickpea flour for when I want to make socca or panelle. Same goes with cornmeal—or at least it used to. I’d leave a never-quite-empty bag hanging around in case I made skillet cornbread to accompany chili. Now I can hardly keep a bag in my house. Why? I figured out it’s useful for all sorts of things besides cornbread, from biscotti to pancakes to pudding.

But first things first: maybe you want to make cornbread. And why not? Corn bread is delicious, and we’re coming up on BBQ season. You’ll need something to mop up that sauce.

Sweet Versions

Brown Butter Cornbread
Sage and Honey Skillet Cornbread
Pumpkin Cornbread
Gluten-Free Maple Almond Cornbread

Savory Versions

Basic Corn Bread (without sugar)
Jalapeño Jack Cornbread
Gluten-Free Cornbread
Cheese and Pepper Cornbread

What else can you make? Well muffins, for one (and we’ve got recipes for sweet, savory, and sausage-stuffed), and other breakfast items (johnny cakes, pancakes, and spoon bread) and full on dessert (plum cake, Indian pudding, and more). Scroll on down to see all the ways you can use this versatile ingredient.


Old Bay Corn Muffins
Corn Muffins with Candied Bacon
Buttermilk Corn Muffins
Sausage-Stuffed Corn Muffins
Scallion and Cheese Corn Muffins
Corn Dill Mini Muffins

Other Breakfast Dishes

Johnnycakes (Cornmeal Pancakes) with Chili Syrup
Cornmeal Pancakes with Honey, Salt and Cracked Black Pepper
Spider Cake (New England Skillet Corncake)
Food52’s Warm Custard Spoon Bread


Cornmeal Cherry Biscotti
Plum-Cornmeal Cake with Plum Sorbet
Indian Pudding
Cornmeal Biscotti with Dried Cranberries and White Chocolate
Jalapeño Cornbread Whoopie Pies with Honey Buttercream
80-Cent Citrus Corn-Muffin Madeleines with Raspberry Confiture
White Chocolate Dipped Lemon-Almond Biscotti

Have another great way to use cornmeal? Share your tricks in the comments section below!

All products linked here have been independently selected by our editors. We may earn a commission on purchases, as described in our affiliate policy.

Advice for the Home Gardener from the Help Desk of the
UC Master Gardener Program of Contra Costa County

Client’s Request: I’ve heard that I can use yellow corn meal to control weeds. Is this doable and will it hurt the soil?

Help Desk Response: Thank you for contacting the UC Master Gardener Program Help Desk with your question about cornmeal and weeds. I am going to assume that you mean corn meal gluten (CGM), a by-product of corn starch manufacturing that is marketed to home gardeners for pre-emergent control of weeds, especially in lawns. Yellow corn meal makes great polenta, but won’t do much for weeds!
University of California research has not shown CGM to be an effective weed control strategy, but in a lawn, it may work because it is high in nitrogen and will feed the lawn, making it more dense, and likely crowding out weeds. Lawns already fed with high nitrogen fertilizers probably won’t show any significant benefit from CGM.

CGM will have no effect on already-emerged weeds; it only suppresses some seeds’ ability to sprout. It is sometimes used though where only organic herbicides are permitted, but its effectiveness is still questionable. It should not have adverse effects on soil. Because it is high in nitrogen, it could be beneficial if your soil is deficient in that nutrient.
Better weed control can be achieved by heavily mulching the area, which will prevent weed seeds from sprouting. At this time of the year, late winter, when many of our weeds have already come up, you can try hand-pulling or hoeing out the small weeds. They are always easiest to control when they are small. This link will give you great information from UC about weed management in the landscape: The key to successfully reducing the weed problem in future years is to make sure none of this year’s weeds go to seed.
Weeds in our gardens are frustrating and seem to be extra-abundant this year because of all the rain we’ve had. Good luck!
Help Desk of the UC Master Gardener Program of Contra Costa County (SEH)
Don’t miss our 2017 Great Tomato Plant Sale:

Cornmeal isn’t usually the first thing that comes to mind when thinking of safe and natural ways to care for our gardens. However, applying cornmeal to soils, certain plants and even water can be beneficial in a number of ways. Let’s take a look at how you can put cornmeal to work for you whether you have a small garden in the backyard or you’re creating self-sufficient homestead.

Weed Control

Cornmeal contains compounds that prevent many species of weed seeds from binding with the soil and germinating. However, it’s not as effective when it comes to killing weeds that have already been established. The trick is to apply the cornmeal on soil before weeds produce seeds so they can’t take root in the future. Keep in mind that seeds from weeds can travel great distances, so even if you don’t have any near your garden, seeds can be deposited from sources upwind.

It’s also important to note that you’ll need “gluten cornmeal” as opposed to the stuff we have in our pantries and stockpiles. Unfortunately, the concentration of weed-killing compounds in these products is too low to be effective.

Ant Killer

Regular cornmeal is widely-considered to be a safe and effective way to kill a number of ant species, but the jury is out on exactly why it works so well. The general consensus is that ants are attracted to the scent of cornmeal but their digestive systems can’t process the food. However, it’s important to note that cornmeal alone doesn’t work on all species, and some suggest adding some poison to the bait to ensure chances of success. Whether or not you use poison or add other ingredients to baits, the fact that cornmeal can help to keep ant problems under control makes it a fantastic option to consider experimenting with.

Anti-Fungal, Rejuvination

A lot of people are convinced that gluten cornmeal can be used as a natural fungicide. There are also a lot of reports that cornmeal can help to rejuvenate dying or struggling plants or restore brown patches of grass. There are also a lot of reports that these claims are unfounded, so it’s really anyone’s guess as to whether or not cornmeal can prevent the spread of disease. However, cornmeal does nourish the soil, and there are a number of “cornmeal treatment” recipes out there that are definitely worth trying out.

Algae Control

One thing that almost everyone can agree on is that cornmeal is a great way to control algae in ponds. Cellulose in cornmeal binds with excess phosphorous in the water, and this helps to bring chemicals back into balance and inhibit the growth of algae. However, it’s important to note that too much cornmeal can also reduce oxygen levels in the water, and this can have a harmful effect on fish. As a general rule of thumb, you should start with less than 5lbs of cornmeal per 1000sf of surface area and work your way up from there.


Finally, consider sprinkling in some cornmeal between layers of compost, and add a little bit more as you stir up the pile. Cornmeal contains a lot of compounds that bacteria and other microbes love to consume, and this can make the process of decomposition more efficient. It can also contribute to the richness of the compost and its effectiveness as you use it in the future.

While some of these options may not be practical or effective in every situation, they illustrate how cornmeal has a number of uses outside of the kitchen or in a feed trough. Take some time to learn more about how you can benefit from having some extra cornmeal on hand. Chances are that you’ll be surprised with what you come across.

One of the most effective organic gardening tools is also one of the most controversial

One of the most effective organic gardening tools is also one of the most controversial. Whether it’s black spot on roses, purple spots and yellow leaves on photinia and Indian hawthorn, brown patch disease on St. Augustine grass, early blight on tomatoes, or damping off in newly planted seedlings, cornmeal is a powerful tool.

Toxic fungicides such as Daconil and Bayleton or heavy metal products like copper sulfate are unnecessary. They kill beneficials as well as pathogens. Cornmeal doesn’t work by killing, but by stimulating beneficial microorganisms.

The Texas A&M AgriLife Research & Extension Center in Stephenville made the discovery and passed it along. Joe McFarland’s staff noticed less disease on experimental peanuts when those crops followed corn in the crop rotation.

In that A&M research lab, grocery-store cornmeal was used. McFarland, after some prodding, told me the best results came from the Aunt Jemima brand. That didn’t mean much to me until a Denton cornmeal company I helped with a horticultural product informed me that Aunt Jemima had more bran and germ particles than other products.

That’s what gave me the idea to use whole ground cornmeal in the garden. Cornmeal works by providing and stimulating a beneficial fungus called trichoderma. All cornmeal will work, but whole ground works best because the bran and germ haven’t been removed. Much of the cornmeal at grocery stores is just the starchy inside of the corn kernel and not as effective for disease control.

Granular corn gluten meal granular is a powerful natural “weed and feed” fertilizer.(Howard Garrett)

Whole ground cornmeal should be used in bed preparation at 20 to 30 pounds per 1,000 square feet as a deterrent to soil-borne plant diseases. It can be used as the primary bed prep material or mixed with any of the other organic amendments. It also works around existing plants as a disease fighter, mild organic fertilizer and soil builder.

Cornmeal tea can also be used for disease control. Soak 1 cup of whole ground cornmeal in 5 gallons of water for an hour, strain out the solids, and spray plants or drench on the soil around plants.

Corn gluten meal (as opposed to cornmeal) is a powerful natural “weed and feed” fertilizer and is available in powdered and granular forms. Granular is less effective, but much less messy to use. Broadcast either at 20 pounds per 1,000 square feet before weed seeds germinate in early spring and fall, or anytime you have bare soil in new beds. It prevents weeds and is an excellent organic fertilizer with an analysis of almost 9-1-1. For best results, it should be watered in after application and then go through a short drying period. By the way, it’s time for the fall application on turf.

Cornmeal converts quickly and efficiently to sugar, and the beneficial trichoderma fungus benefits from that process. That’s why I have it in my sugar amendments category, but also why you shouldn’t eat too much.


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