Large Patch Disease: Control with Two Fall Fungicide Applications

Susceptible Turfgrasses

Large Patch Disease primarily affects specific types of turfgrasses, making it essential to know if your lawn is at risk. The turfgrasses most susceptible to this disease include:

• Centipedegrass
• Zoysiagrass
• St. Augustinegrass
• Seashore paspalum

These grasses are particularly vulnerable in regions where the weather conditions in late fall and early spring are favorable for disease development. Large Patch Disease typically thrives when soil temperatures drop to around 70°F, often during periods of extended leaf wetness. Regular lawn disease and fungus control can help mitigate the impact of these conditions.

Recognizing the Symptoms of Large Patch Disease

Identifying Large Patch Disease early can help prevent severe damage to your lawn. The symptoms are most noticeable in the spring as the grass begins to green up. Look out for the following signs:

• Reddish-brown or black lesions on the basal leaf sheaths
• Blighted rings of turfgrass, ranging from 5 inches to 10 feet or more in diameter
• Patches that appear reddish-brown to yellow, sometimes with an orange ring around them
• Leaves that easily detach from the stems
• A stark contrast between blighted patches and healthy, dormant turf in winter
• Limited recovery of affected areas during spring green-up

Infected warm-season grasses rarely show leaf spots, but they may have rotted leaf sheaths near the soil surface, causing the leaves to pull free with little resistance. For more detailed information, visit the NC State Extension page.

Factors That Contribute to Large Patch Disease Development

Several environmental and cultural factors can increase the likelihood of Large Patch Disease developing in your lawn. Understanding these factors can help you take preventative measures:

• Excessive nitrogen in the fall and spring
• Poor soil drainage and waterlogged areas
• Over-irrigation leading to prolonged leaf wetness
• Excessive thatch accumulation
• Low mowing heights that stress the turf

By being mindful of these factors and considering professional lawn and landscape maintenance services, you can reduce the risk of Large Patch Disease and keep your lawn healthy and vibrant.

Cultural Control Practices for Large Patch Disease

While fungicides play a crucial role in controlling Large Patch Disease, cultural practices are equally important. Implementing these strategies can help you manage the disease more effectively:

• Avoid nitrogen applications in the fall and spring to prevent rapid, susceptible growth.
• Improve soil drainage by avoiding planting in low-lying, saturated areas or installing subsurface drainage systems.
• Irrigate wisely by watering only when necessary to prevent severe drought stress.
• Control traffic on the lawn to avoid compaction and aerify regularly to maintain soil drainage.
• Mow at recommended heights to reduce stress on the turf and keep thatch under control. Consider using a professional lawn mowing service to ensure optimal mowing practices.

These cultural practices are the foundation of a healthy lawn and can significantly reduce the impact of Large Patch Disease.

Management Tips for Large Patch Disease

Proper lawn management is essential for preventing and controlling Large Patch Disease. Here are some expert tips to keep your lawn disease-free:

1. Apply nitrogen sparingly during the summer and avoid it altogether in the fall. A fertilization service can help tailor the correct nutrient regimen for your lawn.
2. Delay spring nitrogen applications until Large Patch Disease is no longer active.
3. Vertical cut zoysiagrass after it has fully greened up, followed by a light nitrogen application to aid recovery.
4. Promote sunlight and air circulation by trimming back overgrown areas and improving drainage.
5. Avoid overwatering and keep thatch levels in check to reduce disease risk.

Integrating these tips with regular lawn treatment can help maintain a healthy, disease-resistant lawn.

Chemical Control: Fungicides for Large Patch Disease

Preventative fungicide applications are a key component of controlling Large Patch Disease. Timing is critical, especially in the fall. Here’s how to use fungicides effectively:

• Monitor soil temperatures to determine the right time to apply fungicides. For Centipedegrass and St. Augustinegrass, apply fungicides when soil temperatures drop to 80°F for five consecutive days, typically in September and October. For Zoysiagrass, wait until soil temperatures drop to 70°F for five consecutive days, usually in October and November. You can use the Soil Temperature Maps to track soil temperatures in your area.
• Apply fungicides twice in the fall, spaced 28 days apart, to achieve season-long control. In severe cases, continue applications every 4-6 weeks as long as soil temperatures remain above 50°F.
• Use at least 2 gallons of water per 1,000 square feet during application, with higher volumes improving the fungicide’s effectiveness.

For best results, consider integrating these chemical controls with professional lawn care services that include targeted weed control and fungicide applications.

Fungicides for Control

Selecting the right fungicide is essential for effectively managing and controlling Large Patch Disease in your lawn. The table below provides a comprehensive list of recommended fungicides, categorized by their effectiveness and active ingredients. 

These products can be found at major retailers, such as big box stores, Site One, Triangle Chemical, landscape supply stores, and Amazon. By following the label instructions meticulously and choosing a product suited to your lawn’s specific needs, you can maintain a healthy, disease-free lawn throughout the season.

This streamlined table provides a clear overview of fungicide options to help you select the best product for controlling Large Patch Disease in your lawn.

Conclusion: Protect Your Lawn from Large Patch Disease

Large Patch Disease can be a significant challenge for warm-season turfgrasses, but with the right combination of cultural practices and well-timed fungicide applications, you can protect your lawn from this damaging disease. By staying vigilant and taking action when soil temperatures begin to drop in the fall, you can keep Large Patch Disease at bay and enjoy a healthy, beautiful lawn year-round.

Don’t wait until it’s too late—call us today or fill out our estimate request form to ensure your lawn stays in top shape! Our team of lawn care experts is here to help you manage Large Patch Disease and maintain the lush, green lawn you deserve with comprehensive lawn care services that cover all aspects of turf health.