Ask the Experts Understanding Brown Patch and Its Impact on Texas Lawns October 2, 2024 Brown Patch fungal disease is a common and destructive lawn disease that affects various types of grasses, particularly St. Augustine grass, which is widely used in Texas. This fungus can harm your lawn, causing brown patches that ruin the look of your yard. Understanding what Brown Patch is, how it affects different grass types, and how to prevent and treat it is essential for maintaining a healthy and vibrant lawn. What is Brown Patch Fungal Disease? Brown Patch is caused by the fungus Rhizoctonia solani. This pathogen thrives in warm, humid conditions, which makes Texas lawns particularly vulnerable during the late summer and early fall. The disease primarily affects cool-season grasses like tall fescue, ryegrass, and warm-season grasses such as St. Augustine, Bermuda, and Zoysia grass. How the Fungus Spreads The Rhizoctonia solani fungus spreads through spores that are carried by wind, water, and even lawn equipment. When environmental conditions are favorable—such as prolonged periods of humidity, temperatures between 70-90°F, and excess moisture—the spores germinate and infect the grass, leading to the characteristic brown patches. Signs and Symptoms of Brown Patch Identifying Brown Patch early is crucial to prevent extensive damage to your lawn. Here are the common signs and symptoms to watch for: Circular Brown Patches: The most noticeable symptom is the appearance of circular brown patches, ranging from a few inches to several feet in diameter. These patches often have a dark brown border and a lighter brown or tan center. Wilting and Blighted Grass: The grass within the affected patches may wilt, turn yellow, and eventually die, leaving behind a thinned, blighted area. Leaf Blades with Lesions: Upon closer inspection, you may notice lesions on the leaf blades. These lesions are usually tan or brown with a dark brown margin, a clear indication of fungal infection. Rapid Spread: Brown Patch can spread quickly under the right conditions, causing extensive damage to large areas of your lawn in a short period. How Brown Patch Affects Different Types of Grasses Brown Patch can affect various grass types, but St. Augustine grass, being a popular choice in Texas lawns, is particularly susceptible. Understanding how this disease impacts different grass varieties can help you manage and protect your lawn more effectively. St. Augustine Grass St. Augustine grass is a warm-season turfgrass that is widely used in Texas due to its shade tolerance and lush, green appearance. However, it is highly susceptible to Brown Patch, especially during the warm, humid months. The disease can cause large, unsightly brown patches that detract from the beauty of your lawn. The thick, dense growth of St. Augustine grass can create a favorable environment for the fungus, especially if overwatered or over-fertilized with nitrogen-rich fertilizers. Bermuda and Zoysia Grass Bermuda and Zoysia grass, also common in Texas, are more drought-tolerant and have a lower risk of Brown Patch compared to St. Augustine. However, they are not immune. During periods of excessive moisture and warm temperatures, these grasses can also fall victim to the disease. Infected areas may recover more quickly with proper care, but preventative measures are still necessary. Tall Fescue and Ryegrass Tall fescue and ryegrass are cool-season grasses that can also be affected by Brown Patch. These grasses are often used in overseeding and are more susceptible during their growing season in cooler months. The disease can cause thinning and patchy areas, making the lawn look uneven and unhealthy. Preventing Brown Patch Fungal Disease Preventing Brown Patch requires a combination of proper lawn care practices and environmental management. By taking proactive measures, you can significantly reduce the risk of this disease affecting your lawn. Proper Irrigation Techniques Water your lawn early in the morning to allow the grass to dry throughout the day. Avoid watering in the late afternoon or evening, as excess moisture overnight creates an ideal environment for fungal growth. Ensure your lawn has good drainage to prevent water from pooling in low areas, which can exacerbate the problem. Mowing Practices Mow your lawn regularly and keep the grass at the recommended height for the specific type of grass you have. For St. Augustine grass, this typically means mowing to a height of 2.5 to 4 inches. Mow when the grass is dry to avoid spreading the fungus through clippings and equipment. Fertilization and Soil Management Apply a balanced fertilizer to your lawn, avoiding excessive nitrogen application, which can promote lush, tender growth that is more susceptible to fungal diseases. Regular soil testing can help you maintain the proper soil pH and nutrient balance, which are crucial for a healthy lawn. Aerate your lawn annually to reduce soil compaction and improve air circulation. Treating Brown Patch Fungal Disease If Brown Patch has already appeared on your lawn, prompt treatment is necessary to prevent further damage. Here are some effective treatment options: Chemical Fungicides Applying fungicides is one of the most effective ways to control Brown Patch. Look for fungicides specifically labeled for Brown Patch control and follow the manufacturer’s instructions for application rates and timing. Fungicides containing active ingredients such as azoxystrobin, or propiconazole can help manage the disease. Reapplication may be necessary, especially during periods of favorable conditions for fungal growth. Natural Treatments For those who prefer organic or natural lawn care methods, some natural treatments can help reduce the severity of Brown Patch. Neem oil and other organic fungicides can provide some level of protection, though they may not be as effective as chemical fungicides for severe infestations. Maintaining overall lawn health through proper watering, mowing, and fertilization is crucial for these treatments to be effective. Lawn Maintenance and Recovery In addition to fungicide applications, maintaining proper lawn care practices will help your lawn recover from Brown Patch damage. Water deeply but infrequently to encourage a strong root system, and avoid over-fertilizing. If necessary, overseed affected areas with a mix of compatible grass seeds to promote recovery and fill in bare patches. Hire a Professional Landscaper Regular monitoring, proper lawn care, and timely treatment will help ensure your lawn remains lush, green, and disease-free throughout the year. If you’re dealing with a severe infestation or are unsure about the best course of action, consider consulting a professional lawn care service like Southern Botanical to keep your lawn in top condition.