How to Prevent Lawn Disease During a Drought
As the summer heat intensifies and rainfall becomes scarce, North Carolina lawns can face a host of challenges. Drought conditions not only stress your grass but can also make it more susceptible to various diseases. According to the North Carolina Climate Office, the state has experienced significant drought periods in recent years, with about 28% of the state facing moderate to severe drought conditions in 2022[1]. If you're noticing brown patches or other unusual symptoms in your warm-season lawn, you're not alone. Let's dive into some common lawn diseases that tend to crop up during dry spells and what you can do about them.
Prevalent Lawn Diseases in Drought Conditions
Brown Patch: Not Just a Cooler Weather Problem
While brown patch is often associated with cool-season grasses and humid conditions, it can also affect warm-season grasses like St. Augustine and zoysia during drought stress. The disease appears as circular brown areas that can grow quite large if left unchecked. Studies have shown that brown patch can affect up to 25% of residential lawns in the southeastern United States during periods of drought[2].
During drought, your grass is already struggling, and brown patch can take advantage of this weakness. The key to managing brown patch is maintaining proper watering practices. When you do water, do it deeply but infrequently to encourage deep root growth. This helps your lawn better withstand both drought and disease pressure.
Dollar Spot: Small but Mighty
Don't let the name fool you – dollar spot can cause significant damage to your lawn. This fungal disease creates small, circular patches about the size of a silver dollar (hence the name). In drought conditions, these patches can multiply and merge, leaving larger areas of your lawn looking worse for wear.
Bermudagrass and zoysia are particularly susceptible to dollar spot during dry periods. The disease thrives when there are cool nights with heavy dew followed by hot, dry days – a common occurrence during North Carolina summers. Research indicates that dollar spot can reduce turfgrass quality by up to 30% in affected areas[3].
To combat dollar spot, focus on proper fertilization. A balanced approach to nitrogen application can help your grass fight off the fungus. Also, when you do water, do it early in the morning so the grass blades have time to dry during the day.
Pythium Root Rot: The Underground Menace
While the symptoms of pythium root rot show up above ground as wilting and yellowing grass, the real damage happens below the surface. This soil-borne fungus attacks the roots of your grass, making it difficult for the plants to take up water and nutrients – a particular problem during drought.
Centipedegrass, a popular choice in eastern North Carolina, is especially vulnerable to pythium root rot. The disease can be exacerbated by overwatering, which might seem counterintuitive during a drought. However, desperate homeowners sometimes compensate for lack of rain by watering too frequently, creating the perfect environment for pythium to thrive. Studies have shown that pythium root rot can reduce root mass by up to 60% in affected areas[4].
To prevent pythium root rot, improve your soil drainage and avoid overwatering. If you're dealing with compacted soil, consider aerating your lawn to improve water penetration and root health.
Fairy Ring: The Mysterious Circles
Have you ever noticed perfect circles of dark green grass in your lawn, sometimes accompanied by mushrooms? You might be dealing with fairy ring. While not always harmful, during drought conditions, fairy ring can prevent water from penetrating the soil, leading to dry, dead grass within the circle.
Fairy ring can affect all types of warm-season grasses in North Carolina. The fungus that causes it feeds on organic matter in the soil, not on the grass itself. However, it can create a water-repellent layer in the soil, which is particularly problematic during dry spells. Research has shown that fairy ring can reduce water infiltration rates by up to 70% in affected areas[5].
Managing fairy ring often involves core aeration and the application of a wetting agent to help water penetrate the soil. In severe cases, you might need to physically remove the affected soil and resod the area.
How to Care for Your Lawn During a Drought
While each of these diseases has its own specific management strategies, there are some general practices that can help keep your warm-season North Carolina lawn healthy during drought conditions:
Water wisely: When you do water, do it deeply and infrequently. This encourages deeper root growth, making your lawn more resilient to both drought and disease. The North Carolina Cooperative Extension recommends watering to a depth of 4-6 inches, which typically requires about 1 inch of water per week[6].
Mow high: Raising your mower blade helps protect the grass roots from heat stress and conserves moisture in the soil. For most warm-season grasses in North Carolina, maintain a height of 2.5 to 3 inches during drought periods[6].
Avoid evening watering: If you need to water, do it early in the morning to allow grass blades to dry during the day, reducing the risk of fungal growth.
Improve soil health: Healthy soil supports healthy grass. Consider adding organic matter to your soil to improve its structure and water-holding capacity. Research shows that increasing soil organic matter by just 1% can increase water-holding capacity by up to 20,000 gallons per acre[7].
Choose drought-resistant grass varieties: When establishing or overseeding your lawn, opt for grass varieties that are well-suited to North Carolina's climate and can better withstand periods of drought. Bermudagrass and zoysia are particularly drought-tolerant options[6].
Does Your Lawn Need a Little TLC This Summer?
Remember, a stressed lawn is more susceptible to disease. By maintaining good lawn care practices even during drought conditions, you can help your grass stay healthier and more resistant to these common lawn diseases.
If you're unsure about what's causing problems in your lawn or how to address them, don't hesitate to reach out to our team here at Triangle Lawn Care. We provide lawn care in Chapel Hill, Raleigh, Durham, Holly Springs, and throughout the Triangle. Our expert lawn technicians can provide specific advice tailored to your lawn's needs and your local conditions.
With a little knowledge and care, you can help your warm-season North Carolina lawn weather the challenges of drought and come out looking green and healthy on the other side.
[1] https://climate.ncsu.edu/drought/
[2] https://www.turffiles.ncsu.edu/diseases-in-turf/brown-patch-in-turf/
[3] https://www.turffiles.ncsu.edu/diseases-in-turf/dollar-spot-in-turf/
[4] https://www.turffiles.ncsu.edu/diseases-in-turf/pythium-root-rot-in-tur…
[5] https://www.turffiles.ncsu.edu/diseases-in-turf/fairy-ring-in-turf/
[6] https://content.ces.ncsu.edu/carolina-lawns
[7] https://www.nrcs.usda.gov/sites/default/files/2022-10/Soil%20Organic%20…