Why is my grass turning red

The reddening of your grass, commonly called Red Thread, is a fungal disease caused by Laetisaria fuciformis. This condition typically emerges in cool, moist environments, notably when the grass lacks essential nutrients, leading to pinkish-red filaments on the grass. This article is the ultimate guide on red thread, what it looks like, and how to get rid of it in your grass.

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What Is Red Thread and What Does It Look Like?

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Red Thread is a lawn disease caused by the fungus Laetisaria fuciformis. This condition is known for affecting various types of grass, particularly during cool, moist periods, often in late spring through early summer and sometimes in the fall, depending on the climate. The name “Red Thread” is derived from the distinctive symptoms it exhibits: reddish-pink threads or filaments that extend from the grass blades. These threads are the fungus’s mycelium, which can bind infected grass blades together, creating patches of discolored, reddish grass that stand out against the healthy green of the rest of the lawn.

The visual symptoms of Red Thread include:

• Small, irregularly shaped patches of grass that appear pinkish or reddish.
• Grass blades within these patches may look ragged and exhibit pink or red strands, resembling threads.
• Red thread often expands under favorable conditions for the fungus, such as high humidity and low nitrogen levels in the soil.

Red Thread does not typically kill the grass outright; instead, it affects the appearance of the lawn and can weaken the grass, making it more susceptible to other stresses. Managing Red Thread involves improving cultural practices such as proper fertilization to boost nitrogen levels, ensuring good drainage, and aerating the lawn to reduce thatch buildup and enhance air circulation around the grass roots.

How Do I Get Rid of Red Thread?

To effectively combat Red Thread in your lawn, starting with a nitrogen-rich fertilizer is a highly recommended approach. Nitrogen plays a pivotal role in enhancing the health and vigor of your lawn, providing it with the strength to resist and recover from Red Thread infestation. Here’s why a nitrogen-rich fertilizer, often termed as ‘nitrogran,’ is beneficial in this context:

1. Boosts Grass Growth: Nitrogen is a key nutrient that promotes dense, vigorous grass growth. By strengthening the grass, nitrogen-rich fertilizers help it outcompete the Red Thread fungus and recover from any damage it has caused​​.
2. Improves Grass Color: Nitrogen is crucial for chlorophyll production, the green pigment in plants. A well-fertilized lawn will be healthier and have a deeper green color, improving its overall appearance​​.
3. Enhances Disease Resistance: Lawns with adequate nitrogen levels are better equipped to resist diseases, including Red Thread. A balanced supply of nutrients makes the grass less susceptible to fungal pathogens by promoting healthier growth and reducing stress​​​​.

In addition to utilizing a nitrogen-rich fertilizer to bolster lawn health against Red Thread, applying a fungicide is another effective strategy, especially for severe or persistent infestations. Fungicides directly target the fungal pathogens responsible for the disease, offering a chemical means to help control and prevent its spread. Here’s how fungicides can be beneficial:

• Direct Action Against the Pathogen: Fungicides are designed to either kill or inhibit fungal pathogens’ growth. By applying a fungicide specifically labeled for use against Red Thread, you’re taking direct action to reduce the fungal population on your lawn​​.
• Protection for Healthy Grass: Fungicides help protect the uninfected parts of your lawn from becoming diseased by curbing the spread of the fungus. This protective barrier allows your grass to remain healthy and continue growing without the added stress of fighting off Red Thread​​.
• Aids in Recovery: While fungicides do not repair the damage already done by Red Thread, reducing the fungal load gives your lawn a better chance to recover. With fewer pathogens, the grass can use its energy for growth and repair instead of defense​​.

How Do I Prevent Red Thread In My Lawn?

While fungicides can be powerful in the battle against Red Thread, their overuse is not advisable. Overreliance on chemical treatments can lead to several issues, including the potential development of fungicide resistance in pathogens, harm to beneficial soil organisms, and the possibility of negative environmental impacts. Moreover, fungicides address the symptoms rather than the root cause of the disease. That’s why it’s crucial to focus on cultural practices that prevent Red Thread from taking hold in the first place.

Preventing Red Thread: Best Practices

1. Proper Nutrition: Ensuring your lawn receives adequate nutrition, particularly nitrogen, helps promote vigorous growth and resilience against diseases like Red Thread​​.
2. Watering Wisely: Overwatering or watering at the wrong time can create conditions that favor fungal growth. It’s best to water your lawn deeply but infrequently, preferably in the morning, to allow the grass to dry during the day​​.
3. Regular Mowing: Mow your lawn at the recommended height for the grass type and keep the mower blades sharp. This reduces stress on the grass, making it less susceptible to diseases​​.
4. Improving Air Circulation and Sunlight Penetration: Prune overhanging branches and thin out dense areas to improve air circulation and reduce moisture on your lawn’s surface. More sunlight can also discourage the growth of fungi​​.
5. Aeration and Dethatching: Compacted soil and thick thatch layers can harbor fungi and prevent water and nutrients from reaching the grass roots. Aerating and dethatching your lawn can alleviate these conditions​​.
6. Choosing Resistant Varieties: If you’re establishing a new lawn or overseeding, consider choosing grass varieties more resistant to Red Thread. This genetic resistance can significantly reduce the occurrence of the disease​​.

Will Red Thread Go Away?

Red Thread can go away independently, especially as conditions become less favorable for its growth. This typically happens when the weather becomes warmer and drier, which helps reduce the moisture on which the fungus thrives. Improving your lawn’s overall health and vigor through proper lawn care practices can also help it recover more quickly from a Red Thread infection.

However, while the fungus may disappear, it’s important to address the underlying conditions that allowed it to establish in the first place. Without taking steps to improve lawn health and prevent future outbreaks, Red Thread may return, especially during periods favorable to its growth (cool, moist conditions).

Here are key steps to help ensure Red Thread goes away and stays away:

• Fertilize Appropriately: Providing your lawn with the right amount of nitrogen can encourage healthy growth, making it less susceptible to Red Thread​​.
• Maintain Proper Lawn Care: Regular mowing, aerating, and dethatching can improve lawn health and reduce the likelihood of Red Thread reappearing​​.
• Water Wisely: Avoid overwatering and water early in the day so the grass has time to dry​​.
• Choose Resistant Grass Varieties: Some grass types are less susceptible to Red Thread, so selecting these for new plantings can be beneficial​​.