Treating Necrotic Ring Spot in Highland, Michigan

Necrotic Ring Spot is a persistent turf disease that can impact any lawn in Highland, particularly during the summer months. This disease is caused by the soil-borne fungus Leptosphaeria korrae, which invades grass roots and crowns, leading to the formation of characteristic circular patches of dead grass. These patches often have live grass in the center, which creates a distinctive and unsightly appearance. Over time, if left untreated, Necrotic Ring Spot can spread, damaging the aesthetic and functional quality of lawns.

Understanding Necrotic Ring Spot

Necrotic Ring Spot typically thrives in environments where soil conditions are less than ideal. Lawns with compacted soil and poor drainage provide an optimal environment for the fungus to flourish. Additionally, stressed turfgrass, such as that subjected to drought, low mowing heights, or inadequate fertilization, is more susceptible to infection.

Kentucky bluegrass, one of the most common grass species in Highland lawns, is particularly vulnerable to Necrotic Ring Spot, although other cool-season grasses can also be affected.

The life cycle of Leptosphaeria korrae is an important factor in understanding how to combat Necrotic Ring Spot. The fungus remains dormant in the soil during the winter and becomes active as soil temperatures warm in the spring. The infection primarily occurs in the roots, weakening the grass’s ability to absorb water and nutrients. This leads to the visible symptoms of dead circular patches encircling healthy grass. Since the disease originates below the surface, it can be challenging to detect and treat in its early stages.

Steps for Effective Treatment of Necrotic Ring Spot

1. Soil Aeration

The first and most critical step in treating necrotic ring spot is soil aeration. Aeration involves perforating the soil with small holes to reduce compaction and allow air, water, and nutrients to penetrate deeper into the root zone. This practice not only helps relieve the stress on the turfgrass but also promotes healthier root growth, making the lawn more resilient to fungal infections. Homeowners in Highland should perform aeration in the spring or fall, when the grass is actively growing, to maximize the benefits. If your lawn has a high thatch layer, then lawn aeration should be done in both the spring and fall.

2. Mowing at the Right Height

Maintaining an appropriate mowing height is another key strategy in managing Necrotic Ring Spot. Grass should be mowed at a height of 2.5 to 3 inches, which helps to reduce stress on the turf and promote deeper root development. Cutting the grass too short can weaken it and increase susceptibility to diseases, while allowing it to grow too long can create a habitat for insect pests and other fungi.

3. Fungicide Applications

Fungicide treatments are a necessary component of controlling Necrotic Ring Spot, but timing is crucial. Preventative fungicide applications in early spring, before the fungus becomes active, can significantly reduce the incidence of Necrotic Ring Spot. It is important to select a fungicide that is specifically labeled for use against Leptosphaeria korrae and to follow the manufacturer’s instructions carefully.

For best results, fungicides should be applied when soil temperatures are consistently above 60°F but before symptoms become visible. This proactive approach can help disrupt the life cycle of the fungus and prevent widespread lawn damage. Additionally, homeowners should rotate fungicides with different active ingredients to prevent the development of fungicide-resistant strains of the fungus.

4. Proper Watering Practices

Deep and infrequent watering is recommended to encourage deep root growth. Lawns should receive about 1 to 1.5 inches of water per week, either from rainfall or supplemental irrigation. It is best to water early in the morning to allow the grass to dry out during the day, minimizing the chances of fungal infection.

5. Fertilization

Proper fertilization is essential for maintaining a healthy lawn and preventing Necrotic Ring Spot. Over-fertilizing can lead to excessive thatch buildup and promote disease, while under-fertilizing can weaken the turf and make it more susceptible to fungal infections. Homeowners in Highland may benefit from consulting with a local lawn care professional to develop a lawn fertilization plan tailored to their lawn’s specific needs.

Overseeding with Resistant Grass Varieties

Overseeding is an effective long-term strategy for managing necrotic ring spot. This involves planting grass that has displayed resistance to Necrotic Ring Spot to improve the lawn’s overall health and appearance.

Overseeding should be done in the early fall, when soil temperatures are ideal for seed germination and the new grass has time to establish before winter. Spring overseeding can be done, but if this is performed then a crabgrass pre-emergent treatment should not be applied.

Preventative Maintenance

Preventing Necrotic Ring Spot requires a combination of good cultural practices and vigilance. Regular lawn care, including mowing, aeration, fertilization, and proper watering, is essential for keeping turfgrass healthy. Homeowners should also be on the lookout for early signs of Necrotic Ring Spot, such as small circular patches of yellowing grass, and take immediate action to prevent further spread.

In addition to these practices, reducing lawn stress is key to preventing disease outbreaks. This can include avoiding heavy foot traffic on the lawn and managing thatch buildup. By maintaining a healthy, well-balanced lawn environment, the chances of Necrotic Ring Spot taking hold are greatly reduced.

Conclusion

Necrotic Ring Spot can be a persistent and frustrating problem for homeowners in Highland, but with the right approach, it is possible to manage and prevent this turf disease.

Key strategies include soil aeration, proper mowing, timely fungicide applications, deep watering, and balanced fertilization. Additionally, overseeding with resistant grass varieties and adopting preventative maintenance practices can help create a lush, green lawn that is less susceptible to Necrotic Ring Spot.

By following these comprehensive lawn care practices, homeowners can not only combat existing necrotic ring spot but also prevent future outbreaks. With consistent effort and attention to detail, a healthy lawn can be maintained throughout the year, enhancing the beauty and value of your property.