Does Cornmeal Kill Weeds?

Nov 7, 2023

Welcome to Friendly Organics Canada, your trusted source for specialty food, health market, and organic store products. In this article, we will explore the effectiveness of cornmeal in killing weeds and how you can incorporate it as a natural and eco-friendly solution in your garden.

Understanding the Power of Cornmeal

Cornmeal is a popular ingredient known for its culinary uses, but did you know that it can also be used as a natural herbicide? When applied correctly, cornmeal can impede the growth of weeds and help maintain a weed-free garden.

How Does Cornmeal Work?

The secret lies in cornmeal's ability to suppress weed germination. Cornmeal contains a natural substance called allelopathic compounds, which inhibit the growth of other plants, including weeds. These compounds prevent weed seeds from developing roots, effectively choking them out before they even have a chance to become established.

Applying Cornmeal in Your Garden

To effectively use cornmeal as a weed killer, follow these simple steps:

  1. Choose Organic Cornmeal: Look for organic cornmeal, preferably coarse-ground or stone-ground varieties, as they retain more of the allelopathic compounds.
  2. Prepare Your Garden: Clear any existing weeds or debris from the area you wish to treat. It's important to have a weed-free surface before applying cornmeal.
  3. Apply Cornmeal: Sprinkle a thin layer of cornmeal evenly over the soil, ensuring it covers the desired area. You can use your hands or a spreader for larger areas. Aim for around 1/4 to 1/2 inch thickness of cornmeal.
  4. Water the Area: Lightly water the area to help the cornmeal settle into the soil and activate its weed-suppressing properties. Keep the soil moist but not overly saturated.
  5. Monitor and Reapply: Check the treated area regularly and reapply cornmeal as needed. Cornmeal effectiveness can vary depending on factors such as rainfall, temperature, and weed types. Reapplication may be necessary every few weeks or after heavy rainfall.

The Benefits of Using Cornmeal as a Weed Killer

Using cornmeal as an organic weed killer offers numerous benefits:

  • Natural and Eco-Friendly: Cornmeal is a safe and natural alternative to synthetic herbicides. It does not harm beneficial insects, wildlife, or water sources.
  • Cost-Effective: Cornmeal is often readily available and more affordable compared to commercial weed killers.
  • Long-Term Prevention: Cornmeal creates an environment hostile to weed growth, providing long-term prevention when used consistently.
  • No Chemical Residues: Unlike chemical herbicides, cornmeal breaks down naturally over time, leaving no harmful residues in the soil.

Tips for Successful Weed Control with Cornmeal

Here are some additional tips to maximize the efficiency of cornmeal as a weed killer:

  • Timing is Key: Apply cornmeal before weed seeds have a chance to germinate. Early spring or early fall are optimal times for treatment.
  • Use Pre-Emergent Approach: Cornmeal is most effective as a pre-emergent weed control method. It works by preventing weed seeds from establishing roots, rather than killing existing weeds.
  • Combine with Mulch: Apply a layer of organic mulch, such as straw or shredded leaves, over the cornmeal. This helps improve moisture retention and further suppresses weed growth.
  • Be Patient: Cornmeal takes some time to work. It may take a few weeks to see noticeable results, but with consistent application, you can achieve a significantly weed-free garden.


Cornmeal can be a fantastic addition to your arsenal of natural weed control methods. Its ability to inhibit weed germination and long-term prevention make it an attractive option for eco-conscious gardeners. Remember to choose organic cornmeal, apply it correctly, and monitor its effectiveness to ensure a flourishing, weed-free garden.

At Friendly Organics Canada, we are proud to offer a wide range of specialty food, health market, and organic store products to support your organic gardening journey. Explore our website for high-quality organic products that promote both sustainable living and a healthy lifestyle.

Disclaimer: This information is provided for educational purposes only and should not be considered as professional gardening advice. Always consult with a gardening expert or local horticulturist for personalized recommendations and guidance.

does cornmeal kill weeds
Femi Olajiga
Interesting, never thought cornmeal!
Nov 10, 2023