Managing Brown Patch on St. Augustine Grass: Effective Cornmeal Treatment and Other Solutions

St. Augustine grass is a popular choice for warm-season lawns due to its durability and ability to thrive in a variety of conditions. However, just like any other grass species, it can fall victim to various issues, such as brown patches. In this article, we will explore the causes of these brown patches and provide an effective home remedy using cornmeal. We will also discuss alternative methods to promote a healthy, lush lawn.

What Causes Brown Patches on St. Augustine Grass?

Poor drainage: Excess moisture in the soil can lead to root rot and other fungal infections, resulting in brown patches.

Poor soil fertility: Imperfect soil composition can make it difficult for grass to get the nutrients it needs, leading to patches of brown grass.

Overwatering or underwatering: Improper irrigation can cause grass to dry out or drown, manifesting as brown patches.

Moderate to severe grass diseases: Fungal pathogens, such as Rhizoctonia solani, can cause brown patch disease.

Thatch accumulation: A thick layer of dead grass can block air, water, and nutrients, leading to brown patches.

Sunscald: Direct sunlight on grass that is not well-soaked can lead to sun-dried areas turning brown.

Mites: Certain mites feeding on the roots and leaves of St. Augustine grass can cause brown patches.

How to Treat Brown Patches with Cornmeal

Cornmeal has been used as a natural remedy for various lawn issues due to its high phosphorus content (about 60% by weight) and highly absorbent properties. It helps to enhance the roots' ability to take up nutrients and combat fungal infections. Here's how to use it to treat brown patches on St. Augustine grass:

Step 1: Prepare the Cornmeal Solution

For a 1000 square foot lawn, mix approximately 15 to 20 pounds of cornmeal with water to create a slurry. This mixture should be quite thick, so it can be spread with a rake or spreader.

Step 2: Apply to the Affected Area

Spread the cornmeal mixture evenly over the brown patches. Ensure that the mixture is applied over a 1000 square foot area for best results.

Step 3: Allow Time for Treatment to Work

Give the application 3 to 4 weeks to take effect. During this time, avoid excessive watering or fertilizing, as this may interfere with the effectiveness of the cornmeal.

Step 4: Monitor Progress and Repeat if Necessary

After 3 to 4 weeks, observe the grass for improvement. If the brown patches have not cleared up, you may need to reapply the cornmeal treatment.

Alternative Methods for Treating Brown Patches

While the cornmeal method is a natural and effective way to combat brown patches, there are other approaches homeowners can consider to promote healthier grass growth:

1. Proper Irrigation

Ensure your irrigation system is set up correctly to avoid overwatering or underwatering. Water in the mornings or evenings to reduce evaporation and allow the grass to dry before nightfall.

2. Soil Testing and Fertilization

Conduct a soil test to determine the nutrient levels and pH of your lawn. Based on the results, apply appropriate fertilizers to correct any deficiencies. Consider using organic options to promote long-term soil health.

3. Aeration

Lawn aeration involves removing small plugs of soil from the lawn to improve air, water, and nutrient movement. This can help reduce thatch build-up and promote healthier grass growth.

4. Disease Control

If fungal diseases are the culprits behind your brown patches, you may need to use fungicides. Consult with a local garden center or lawn care specialist to find suitable fungicides for St. Augustine grass.

5. Thatch Removal

If the thatch layer is too thick, you may need to manually remove it with a dethatching tool or rake. This helps improve soil aeration and moisture penetration.

Preventive Measures to Maintain a Lush Lawn

To prevent brown patches in the future, consider the following maintenance steps:

1. Proper Mowing Techniques

Ensure your mower blades are sharp and maintain a consistent mowing height for your St. Augustine grass. Mowing too short can stress the grass and lead to browning.

2. Regular Fertilization

Apply a balanced fertilizer regularly, especially in early spring and late fall, to promote healthy growth. Look for fertilizers with an appropriate N-P-K ratio (nitrogen, phosphorus, and potassium).

3. Mulching

Consider mulching during periods of excessive fall thatch build-up to reduce the amount of organic matter left on the lawn. This can help maintain a healthy lawn.

4. Regular Fungicide Applications

In areas with a history of brown patch disease, consider applying a preventative fungicide in the late spring and early summer to control fungal growth.

5. Encourage Drought Resistance

To improve drought resistance, ensure proper irrigation and choose varieties of St. Augustine grass that are better suited to your climate.

Conclusion

St. Augustine grass, with its vibrant green color and ability to thrive in warm climates, is a popular choice for many homeowners. However, brown patches can be a frustrating issue. Whether you opt for the cornmeal treatment, maintain proper irrigation, or take other preventative measures, you can ensure a healthy, lush lawn. By understanding the causes of brown patches and implementing appropriate solutions, you can enjoy the beauty and vitality of your St. Augustine grass for years to come.