Lawn fungi are a common adversary for gardeners and homeowners, presenting a challenge to maintaining lush, healthy grass. These microscopic enemies thrive under certain conditions, leading to unsightly patches that can devastate a lawn. Understanding the nuances between different fungi, such as brown patch and dollar spot, is essential for effective lawn care. Recognizing the early signs and knowing how to manage these issues can make a significant difference in the health and appearance of your lawn.
What is Brown Patch?
Symptoms and Characteristics of Brown Patch
Brown patch is a fungal disease caused by the pathogen Rhizoctonia solani. This affliction usually appears during warm, humid conditions, primarily affecting cool-season grasses. Symptoms manifest as circular patches of brown, wilted grass that can range from a few inches to several feet in diameter. The affected area may have a smoke ring - a dark, grayish border that is visible in the early morning.
Causes and Conditions that Contribute to Brown Patch
Brown patch thrives in temperatures between 70-90 F, especially when nighttime humidity remains high. Overwatering, poor drainage, and compacted soil exacerbate the problem by creating an ideal environment for the fungus. Excessive nitrogen fertilizer can also contribute to its spread by encouraging rapid, soft growth that is more susceptible to disease.
How to Prevent and Control Brown Patch
Prevention and control of brown patch involve cultural practices and, if necessary, chemical treatments. Improving air circulation, sunlight penetration, and drainage can significantly reduce the risk. Watering in the early morning allows the grass to dry throughout the day, reducing moisture on the leaves. If the problem persists, fungicides may be applied as a preventative measure or to control an active outbreak.
What is Dollar Spot?
Symptoms and Characteristics of Dollar Spot
Dollar spot, caused by the fungus Sclerotinia homoeocarpa, affects a wide range of grasses. This disease is named for the silver-dollar-sized (1-2 inches in diameter) tan or straw-colored spots it creates. The lesions on the grass blades are marked by a distinctive hourglass shape, bleached in color. In severe cases, these spots can merge, causing extensive damage to the lawn.
Causes and Conditions that Contribute to Dollar Spot
Dollar spot favors conditions of high humidity and moderate temperatures, between 60-85 F. It is particularly prevalent during periods of low soil moisture paired with heavy dew, fog, or light rain. Poor soil fertility, especially low nitrogen levels, can increase the lawn's susceptibility to dollar spot.
How to Prevent and Control Dollar Spot
Maintaining balanced soil nutrition is key to preventing dollar spot. Regular, light fertilization, particularly with nitrogen, can help keep your lawn resilient. Adequate watering, especially during dry spells, is important, but it's crucial to avoid overwatering. For established infections, fungicides can be effective, especially when applied at the onset of the disease.
Brown Patch vs Dollar Spot: Key Differences and Similarities
While both fungi thrive under moist conditions, they favor slightly different climates and present distinct symptoms. Brown patch is more prevalent in warm, humid weather, affecting larger areas with a distinctive smoke ring, while dollar spot enjoys moderate temperatures and manifests as smaller, silver-dollar-sized spots. Both diseases can be managed through proper lawn care practices, such as appropriate watering, fertilization, and the use of fungicides when necessary.
Conclusion: Maintaining a Healthy Lawn
The battle against lawn fungi like brown patch and dollar spot is ongoing. Understanding these diseases, their conditions, and management strategies is crucial for maintaining a healthy lawn. Regular monitoring, proper lawn care practices, and timely interventions can keep these fungal foes at bay.
Lobb Alexis is Kenner's best choice for lawn and shrub care. We can handle any issue keeping your lawn from being as healthy and beautiful as possible. Contact us today for a free consultation.
