Red thread fungus, also known as Laetisaria fuciformis, is a common disease that affects lawns, especially in areas with high humidity. If left untreated, red thread can take over large patches of grass and leave unsightly pink or orange threads all over your yard. The good news is that with persistent treatment and good cultural practices, you can get red thread fungus under control and restore your lawn’s health.

Understanding Red Thread Fungus

Red thread gets its name from the pink or orange strands it produces on the grass blades. The threads are made up of the fungus’s spores and mycelium. Optimal conditions for red thread growth include:

High humidity and prolonged leaf wetness
Moderate temperatures between 60-80°F
Low nitrogen fertility in the turfgrass
Established turfgrass under stress

The disease is most active in the spring and fall when the weather is cool and humid. Red thread spreads through spores carried by splashing water, mowers, foot traffic, infected grass clippings, and other means.

Susceptible grass types include fescues, bentgrasses, and perennial ryegrasses. Bermudagrass and zoysia are more resistant.

Preventing Red Thread Fungus

Prevention starts with promoting healthy turfgrass through proper mowing, watering, fertilization, and other cultural practices:

Mow regularly at the recommended height for your grass type. Never cut off more than 1/3 of the blade at once.
Water deeply and infrequently to encourage deeper roots. Avoid frequent light watering.
Fertilize in the spring and fall with a balanced fertilizer following soil test recommendations. Avoid excessive nitrogen.
Improve air circulation and drainage if needed.
Dethatch and aerate compacted areas to reduce moisture retention.
Allow grass to dry fully between waterings and mowings.
Remove clippings to prevent disease spread.
Overseed thin or bare areas to keep turf dense and vigorous.
Reduce turf stress from traffic, heat, drought, etc.

Treating Active Red Thread Infections

If preventive measures have failed and red thread fungus takes hold, you’ll need to treat actively infected areas. Effective treatment options include:

Fungicides

Azoxystrobin, myclobutanil, propiconazole and chlorothalonil are effective chemical fungicides.strictions and instructions.
Apply at first signs of disease and repeat per label directions until fungus is gone.

Organic Options

Neem oil or potassium bicarbonate may suppress red thread. Repeat applications are needed.
Remove diseased grass clumps and debris to reduce spore source.

Cultural Practices

Increase mowing height and fertilization to improve grass health.
Overseed diseased patches to thicken turf.
Improve drainage if soggy areas are prone to the disease.

Be patient, as it can take time for the treatments to work and for new grass to establish. Persistence is key to getting red thread under control so your lawn can return to its former glory.

FAQs About Controlling Red Thread Fungus

What’s the best time to treat red thread fungus?

It’s best to treat red thread as soon as symptoms first appear in spring or fall. Early intervention prevents the disease from establishing and spreading.

How long does it take for antifungal treatments to work on red thread?

You should see gradual improvement within 2-4 weeks after starting fungicide treatments. But it can take several applications over a period of 1-2 months to fully eradicate visible signs of infection.

Does raking out red thread fungus help get rid of it?

Removing infected leaf blades and debris can reduce the spore source. But raking alone will not eliminate the fungus already growing in the soil and plant crowns. Fungicides and cultural practices are needed to fully treat red thread.

Should I reseed areas damaged by red thread fungus?

Yes, overseeding is recommended after fungal treatments to thicken up patches of turf damaged by red thread. Just be sure to address conditions favorable to disease before seeding.

Will red thread fungus go away on its own?

In ideal conditions of low humidity and high temperatures, the disease may resolve on its own. But more often, active intervention is required to rid lawns of persistent red thread infections.

Maintaining a Red Thread-Free Lawn

Be vigilant about monitoring your lawn for early signs of fungal disease. Once you get red thread under control, keep up with good maintenance practices to prevent its return:

Stick to a regular mowing, fertilizing and watering schedule suited to your grass type.
Minimize moisture on leaves by watering early in the day.
Prune trees/shrubs to increase sunlight and reduce humidity.
Remove clippings and debris that harbor fungal spores.
Scout often for disease and treat promptly.
Overseed to maintain dense turf.

With persistence in both prevention and treatment, you can successfully manage red thread fungus and maintain a lush, healthy lawn. Don’t allow this stubborn disease to take over your grass.

Conclusion

Red thread fungus is frustrating, but with a commitment to cultural practices that promote strong turfgrass and diligent treatment at the first sign of disease, you can keep it under control. Always take an integrated approach using proper mowing, fertilizing, watering, and fungicides. Overseeding diseased patches accelerates recovery. While vigilance is required, you can protect your lawn from being overtaken by destructive red thread infections. Healthy grass is resilient grass.

How to Keep Red Thread Fungus From Taking Over Grass