Ways to Prevent Red Thread Fungus from Dominating Your Lawn

Kelly Burke is a certified turf management expert with credentials in organic land care and holds a license for pesticide application.

Are there areas in your lawn that seem to be wilting, featuring pink or reddish strands? This could be an indication of red thread fungus (Laetisaria fuciformis). This lawn disease typically arises from insufficient nitrogen in the soil or from environmental stressors.

Here are various chemical and natural remedies to eliminate red thread fungus:

• Apply the appropriate quantity of nitrogen to nourish the grass.
• Steer clear of excessively damp grass, and ensure that it doesn’t become too dry either.
• Enhance the flow of air and the amount of sunlight.
• Collect clippings from contaminated grass.
• Eliminate excess thatch.
• Minimize foot traffic on the lawn.
• Use fungicide only as a final option.

Methods to Eliminate Red Thread Fungus from Your Lawn

Using chemicals to combat red thread fungus is not advisable for home lawns and is generally unnecessary. Resorting to fungicides should only be considered for severe outbreaks. It’s best to seek advice from a lawn care expert or your local cooperative extension service for guidance on suitable fungicides for your region.

Homeowners frequently seek solutions for getting rid of red thread fungus on their lawns, which tends to appear annually. The key to combating this fungus lies in preventing its growth. While it’s not feasible to eliminate the pathogen or alter the weather, the best approach to managing red thread fungus is to focus on the vulnerable host plant and enhance its resilience through the use of fertilizer.

To effectively manage red thread fungus, it’s essential to fertilize your lawn with the right amount of nitrogen as part of a regular feeding regimen. Applying nitrogen in the fall will support the grass as it begins to grow again in the spring, but it’s important to avoid excessive stimulation of growth as the season ends. Consistent and careful fertilization over a period of two years or more may be necessary to keep red thread fungus at bay in the spring.

Another approach to managing grass health is to prevent extended durations of moisture on the grass. It is advisable to irrigate during the hours of midnight to 6 a.m. Ensure that enough water is applied to saturate the root zone, and refrain from watering again until the turf begins to exhibit early signs of drought stress.

Trim or eliminate trees or bushes to enhance sunlight exposure and airflow. Collect clippings from infected regions while the disease is present and clean mowing equipment after each use to minimize disease transmission.

Ways to Recognize Red Thread Fungus

It manifests as slender, red, thread-like extensions, often likened to antlers, known as sclerotia. The grass typically exhibits a tan or light brown color underneath these red thread formations.

Red thread fungus is often mistaken for a condition known as pink patch. While pink patch is caused by Limonomyces roseipellis and is a distinct disease, it bears a strong resemblance to red thread in terms of symptoms, disease progression, epidemiology, host range, and visual characteristics.

Does Red Thread Fungus Harm Grass?

Although the grass in affected areas may seem lifeless, the red thread fungus does not actually kill the grass. This fungus, which thrives in the thatch and soil, can be transmitted through decaying infected plant matter, mowing, and various mechanical maintenance activities. The pink formations observed in the grass do not penetrate the crown or the roots of the plant, meaning that the fungus does not lead to the grass’s demise.

Optimal Circumstances for an Infestation of Red Thread Fungus

Red thread fungus can be found in various climates, but it tends to be more prevalent in regions that experience significant rainfall or humidity, particularly during late spring to summer. The main factors that promote the growth of red thread fungus include:

• Insufficient nitrogen levels or inadequate fertilization overall.
• Temperatures ranging from 68 to 75 degrees Fahrenheit.
• Elevated moisture levels in the air
• Dim lighting conditions
• Overuse of the grassy areas

Reasons Behind the Presence of Red Thread Fungus in Your Lawn

Nearly every lawn can be affected by red thread turf fungus. Nonetheless, it’s not unusual for certain lawns to experience more problems than those nearby, as a result of varying soil conditions, maintenance practices, and watering habits.

The origins of red thread fungus and various other turf ailments can be comprehended by examining three key elements that form a “triangle” of disease: a vulnerable host, the pathogen or adverse condition, and an environment that promotes disease development.

The grass plants are deficient in nitrogen and are growing at a slower rate compared to previous months. The pathogen resides in the thatch layer of the lawn and cannot be completely eliminated. When the plants are weakened and the conditions of temperature and humidity are conducive to fungal development, the red thread fungus emerges and persists.

Despite being a type of fungus, it does not propagate through spores as typical fungi do. Instead, it infects healthy grass through the growth of mycelium, which resembles the branching roots of fungi. It has the ability to endure harsh conditions by staying dormant within the infected grass.

Grasses Vulnerable to Red Thread Disease

Grasses that thrive in cooler seasons are generally more vulnerable to red thread fungus. Notable types include red fescue, ryegrass, Kentucky bluegrass, and bentgrass. In contrast, warm-season turf grasses show greater resistance to this fungus compared to their cool-season counterparts. For tailored advice, your local cooperative extension service can suggest the most red thread-resistant varieties suited to your region.