Corn Gluten Meal Stops Weeds Organically

May 8, 2018

5 min read

Updated: 6 days ago

Summary

Get ahead of weeds in your lawn and flowerbeds with corn gluten meal, an organic pre-emergent herbicide. It helps stop new weeds from taking root as their seeds sprout. It feeds your lawn, too, without harming your established grass or landscape plants.

Here in North Texas, plan to apply it from mid-February through mid-March and again from mid-September through mid-October. Regular spring and fall applications help you grow a lawn with fewer weeds over time. Corn gluten meal won’t kill weeds already growing, and you should skip areas where you’re starting grass, flowers, or vegetables from seed.

Green front lawn bordered by shrubs and a stone-edged planting bed beside a brick house. — Corn Gluten Meal acts as an all-natural, organic pre-emergent herbicide. Use it twice yearly in spring and fall to prevent weeds from sprouting in your lawn.

Organic Weed Prevention

Any weed expert will tell you that the best way to keep weeds out of your lawn and flowerbeds is to never let them get started. Keeping your turf thick and healthy, and mulching flowerbeds does a lot to help prevent weeds. The other key is regular applications of a pre-emergent herbicide. For organic gardeners, that product is Corn Gluten Meal.

A happy accident back in 1986 led researchers at Iowa State University to discover that Corn Gluten Meal prevents seed germination. Since then, lots of research has been done on whether Corn Gluten Meal is, in fact, an effective weed control, and the answer is a resounding “YES!”

There are some tricks, though. Here’s an overview of what it is and how it works, along with the secrets to getting the most out of it.

Using Corn Gluten Meal Around Kids and Pets

Corn Gluten Meal is a by-product of the corn milling process. Long before it became famous as a weed suppressant, it was used as a supplement in animal feed, including some dog foods. Corn Gluten Meal is 100% organic and safe to apply around pets and children.

Yellow corn gluten meal filling a green lawn spreader. — Corn Gluten Meal is highly effective for weed suppression. plus it provides a natural source of nitrogen.

How Corn Gluten Meal Works

Corn Gluten Meal contains some naturally occurring chemicals called peptides that actually inhibit root formation of a seed at the time of germination.

One application of Corn Gluten Meal keeps working to suppress seed germination for 4 to 6 weeks. (Heavy soils, extended rainy weather, and hot spells may require additional applications. It works on all types of seeds — and only on seeds. It does not harm existing plants. When used correctly, over time you will have fewer broad leaf and grassy weeds, including Crabgrass, Dandelions, Clover, Henbit, and many others.

Because it is non-selective, you should avoid applying it in areas where desirable plants might be germinating. If you plan to overseed your lawn, start flowers, or grow vegetables from seed, be sure to wait at least 6 weeks after applying it.

Yellow dandelion bloom among green foliage. — Dandelions are usually one of the first weeds to appear in the early spring ― a sign that it's time to apply Corn Gluten Meal.

How to Use Corn Gluten Meal

Corn Gluten Meal has a very fine, powdery texture. It's also available in granular form. Marshall Grain offers both the meal and granules.

Either product can be distributed using any type of fertilizer spreader. Apply it to your lawn and, if you wish, to your flowerbeds, directly on any bare earth, and around new plantings.

The powdery meal is a bit messy to apply, especially on windy days. It will look like a layer of pollen on the soil. The granules are easier to spread and much less messy. The granules can also be mixed with water into a paste in your flowerbeds to prevent weeds from sprouting up between plants.

Both types of Corn Gluten contain 9% nitrogen by weight (i.e., 100lbs of corn gluten contains 9lbs of nitrogen) to help make your lawn greener, so it’s a great organic fertilizer, plus it adds organic material for increasing microbial activity. Thanks to this dual function, many people refer to it as an organic “weed and feed” product.

Apply 20lbs per 1000 square feet to make sure you get sufficient coverage.

Iowa State University research shows that the results of using corn gluten meal consistently over time are cumulative. The longer you use it, the better your lawn will look!

Red twin-bell alarm clock sitting in grass beside small white flowers. — *Since most weeds germinate when over-night temperatures are in the mid-50s, it's important to apply Corn Gluten Meal at the right time.*

When to Apply Corn Gluten Meal in North Texas

Timing is critical for both organic and synthetic chemical pre-emergents. Weeds don’t have calendars. They sprout as soon as the weather is right. Sunny days and temperatures in the mid-50’s begin the cycle of germinating and re-seeding. This is the signal that it’s time to put out your pre-emergent.

In North Texas, weed sprouting season usually starts around mid-February and continues throughout the growing season. The process slows down considerably during the heat of summer, but then picks up again when temperatures cool in the fall. All this boils down to the need to treat your lawn at least twice a year — once in the spring and once in the fall.

In spring the best time to apply it is typically between February 15 and March 15, depending on the weather. In fall, it is usually applied between September 15 and October 15, again depending on the weather.

The seedling stage of a weed can last 8 to 15 weeks, depending on temperature and growing conditions. Since they are usually well-hidden within your lawn, this means that the weeds you see in the springtime actually germinated in the fall. Likewise, seeds that germinate in the spring don’t become visible until fall.

Watering After Application

One problem with Corn Gluten Meal can be too much water. Some is necessary, but too much can spoil the job.

Corn Gluten Meal needs to be watered in within 5 days of application. If no rain occurs within that window, you should water it in with 1/4 inch of water. But heavy rain or excessive irrigation will wash it away before it can dissolve into the soil. This means that the watering-in process must also be followed by a dry period of a day or two to prevent the seedling from growing another root. If heavy rain is predicted, it may be best to wait for drier weather before putting it down.

You may prefer to water your lawn before you apply Corn Gluten Meal — especially if you plan to use a broadcast spreader. Being a fine powder, Corn Gluten Meal easily blows around, getting on you and everything else in your yard. Broadcast spreaders cause the powder to fly out to the sides, rather than just dropping straight to the ground, which encourages more mess. Windy days are also problematic. Watering lightly first will help keep the dust to a minimum and make it stick to the lawn immediately.

Corn Gluten Meal Facts

The only 100% organic pre-emergent herbicide available
It only works on seeds. It will not harm existing plants
Safe for people and pets
Timing is critical. Application must be synchronized with weed germination
Must be applied 2x yearly in spring and fall
Provides a slow-release 9% nitrogen source

If you’ve followed these guidelines and used Corn Gluten Meal consistently, over time you can expect weed suppression similar to using a chemical pre-emergent. And you will rest easier knowing that your garden is a safer place for you and your family to enjoy.

Let Us Do It For You

We can take care of your Corn Gluten Meal applications and help keep your lawn and garden healthy with ongoing organic care. Our maintenance services include: