How to Treat Dollar Spot Fungus: Identify, Prevent, and Control It in 2023

Is your once lush, green lawn now spotted with unsightly yellow patches? Don’t despair – you’re not alone! Dollar spot fungus is a common turfgrass disease that affects lawns worldwide. The good news is that with early identification, prevention, and control strategies, you can restore your lawn’s health and keep it looking its best. In this blog post, we will guide you through understanding this pesky fungus, how to inspect your lawn for signs of infection, and how to treat dollar spot fungus with the most effective treatment options available. So let’s dive in and reclaim your beautiful, healthy lawn!

Short Summary

  • Dollar Spot Fungus is a fungal disease that thrives in warm and humid conditions, affecting grass species such as fescue, ryegrass, zoysiagrass, etc.
  • Preventive measures include lawn maintenance practices, thatch management & aeration, and selecting resistant grass cultivars.
  • Treatment options for Dollar Spot Fungus involve organic/chemical fungicides application along with cultural control methods or professional services.

Understanding Dollar Spot Fungus

Dollar spot fungus is a prevalent fungal infection of turfgrass, resulting in discolored grass blades and unsightly lawn patches. Caused by the fungus Sclerotinia homoeocarpa, this disease thrives under warm and humid conditions, making it particularly common during late spring and early summer. While dollar spot can affect all types of turfgrass, it is most commonly observed on bentgrass, Kentucky bluegrass, perennial ryegrass, and tall fescue. Golf courses often face the brunt of this disease, but residential lawns can also suffer significant damage if left untreated.

Understanding dollar spot fungus’s characteristics, causes, and conditions is crucial for accurate identification and effective treatment. In the following sections, we will delve into the specific traits of this fungal disease and the grass species most susceptible to infection.

Characteristics of Dollar Spot Fungus

The primary cause of dollar spot lawn disease is Clarireedia jacksonii, which manifests as small, circular patches that are tan-colored with discolored grass blades. The grass blades affected by the disease display an hourglass-shaped lesion. The lesion has a bleached center and reddish-brown to purplish borders. As these lesions spread, the leaves become girdled, leading to the gradual death of the grass.

Dollar spot can easily be mistaken for other lawn diseases, making accurate identification essential for successful treatment. Look closely for small reddish-brown spots with slightly sunken centers and pale yellow margins when inspecting your lawn for signs of dollar spot. These areas can spread rapidly throughout the entire lawn.

Causes and Conditions for Dollar Spot Fungus

The development of dollar spot fungus is attributed to extended periods of leaf wetness (10-12 hours), heavy dews, and overcast weather. It is most active during humid and warm days with cool nights. The fungus can spread through contaminated lawn care equipment or shoes and wind and grass clippings. These conditions create a perfect breeding ground for dollar spot, making it essential to identify and treat the disease promptly to maintain the health of your lawn and prevent severe damage to the grass.

Some factors contributing to the occurrence of dollar spot fungus include drought stress, low mowing, excessive thatch accumulation, frequent irrigation, low air movement, and temperatures ranging from 60 – 80 degrees Fahrenheit. By understanding these causes and conditions, you can take preventive measures to reduce the likelihood of dollar spot infection and maintain a healthy, lush lawn.

Grass Species Affected by Dollar Spot Fungus

Certain grass species are more prone to dollar spot infection. All other species of warm- and cool-season grasses are also susceptible. Fescue, ryegrasses, and zoysiagrasses have been observed to be susceptible, with creeping bentgrass, perennial ryegrass, and Kentucky bluegrass being particularly vulnerable to dollar spot.

Knowing which grass species are most susceptible to dollar spot can help inform your prevention strategies and treatment approach. Selecting resistant grass cultivars and implementing proper lawn care practices can minimize the risk of dollar spot infection and maintain a healthy, vibrant lawn.

Lawn Inspection and Identification

Inspecting your lawn for signs of dollar spot is the first step in stopping this disease in its tracks. Accurate identification is crucial to ensure you apply the correct treatment method and prevent further damage to your lawn.

This section will discuss how to inspect your lawn for dollar spot, differentiate it from other lawn diseases, and confirm your diagnosis.

Inspecting Your Lawn

When inspecting your lawn for signs of dollar spot, look for light tan, roughly circular patches on the lawn caused by the fungus Clarireedia jacksonii. These patches may begin as small as 2 to 6 inches in width but can expand into large, irregular patches if left untreated. The grass blades affected by dollar spot will appear water-soaked and display yellow spots ringed in reddish-brown. Additionally, cobweb-type growth may be visible between blades.

If you’re uncertain about whether your lawn is affected by dollar spot, it’s always a good idea to consult a professional for assistance. They can help confirm the diagnosis and recommend the most appropriate treatment plan to restore your lawn to its former glory.

Differentiating Dollar Spot from Other Lawn Diseases

Dollar spot fungus can be distinguished by its round, bleached-out, or straw-colored spots, which range from the size of a quarter to the size of a silver dollar, along with the unique hourglass-shaped lesions on grass blades. However, other lawn diseases may present similar symptoms, making it important to differentiate dollar spot from diseases like brown patch, powdery mildew, red thread, snow mold, and fairy ring.

One key distinction between dollar spot and other lawn diseases is the appearance of the affected grass blades. For example, Pythium blight produces dark, bronze, or orange-colored spots with a greasy sheen, while dollar spot fungus produces white or straw-colored silver dollar spots.

Accurately identifying dollar spot ensures that you apply the correct treatment methods and avoid causing further damage to your lawn.

Confirming Dollar Spot Diagnosis

To confirm the diagnosis of dollar spot fungus, observe the round, bleached-out or straw-colored spots on your lawn and any white mycelium appearing on the affected area in the morning, which then fades to a brown, tannish color after sun exposure. The blade itself is usually of a purple or light-brown hue. If left untreated, these spots will propagate and coalesce to form expansive patches of dead grass.

Accurate identification is essential to ensure that you apply the correct treatment methods and prevent further damage to your lawn. If you’re uncertain whether your lawn is affected by dollar spot, consult a professional for assistance and recommendations on the best action.

Prevention Strategies for Dollar Spot Fungus

Prevention is key when it comes to managing dollar spot fungus. By implementing effective lawn maintenance practices, managing thatch and aeration, and selecting resistant grass cultivars, you can minimize the risk of dollar spot infection and maintain a healthy, vibrant lawn.

This section will discuss various prevention strategies that can help protect your lawn and keep it looking its best.

Lawn Maintenance Practices

Proper lawn maintenance practices play a crucial role in preventing dollar spot fungus. Mowing at the appropriate height for your grass type, providing sufficient irrigation during arid periods, and eliminating morning dew from the leaves daily are recommended to keep your lawn healthy and resistant to dollar spot infection.

In addition to these practices, applying nitrogen fertilizer can also help prevent dollar spot by promoting a healthy lawn and hindering the fungus from thriving in lawns with inadequate lawn food. Golf courses established with creeping bentgrass or annual bluegrass should apply 0.5 lb of nitrogen per 1000 feet2 during each growing month. This amount is essential for optimum putting green maintenance.

It is recommended to carry out irrigation in the early morning, between 3-8 AM. This helps to keep the leaf wetness periods short.

Thatch Management and Aeration

Thatch management is essential in preventing dollar spot fungus, as excess thatch can create favorable conditions for fungal growth. Thatch is the layer of dead organic material that accumulates between the soil surface and the grass’s green shoots or stems. Preventing thatch buildup through appropriate fertilization, pesticide use, mowing at the correct height, and topdressing.

Core aeration is the recommended course of action for removing thatch buildup. Aeration helps decrease compaction, augment water and nutrient absorption, and foster healthy root development. By implementing these thatch management and aeration practices, you can maintain a healthy, well-aerated lawn that is less susceptible to dollar spot and other fungal diseases.

Selecting Resistant Grass Cultivars

Choosing grass cultivars resistant to dollar spot can further reduce the risk of infection. Some grass species, such as perennial ryegrass and tall fescue, are less susceptible to dollar spot than other commonly used species. Certain cultivars of creeping bentgrass have also demonstrated increased resistance to dollar spot, as revealed by research conducted at Penn State.

When selecting a grass cultivar for your lawn, consult university recommendations or regional cultivar trials conducted by the National Turfgrass Evaluation Program, or local universities. By selecting resistant grass cultivars and implementing proper lawn care practices, you can minimize the risk of dollar spot infection and maintain a healthy, lush lawn.

Treatment Options for Dollar Spot Fungus

If your lawn is already affected by dollar spot fungus, don’t worry – there are various treatment options available to help you regain control and restore your lawn’s health.

In this section, we will discuss the use of organic and chemical fungicides, cultural control methods, and professional treatment services to effectively treat dollar spot and prevent its recurrence.

Organic and Chemical Fungicides

Fungicides can play a vital role in controlling and preventing dollar spot. Both organic and chemical fungicides, such as Propiconazole 14.3, Clearys, or Eagle 20EW, are recommended for treating dollar spot fungus. However, fungicides are most effective when used as a preventative measure, rather than a curative treatment for lawn disease.

To impede or delay the emergence of fungicide resistance in dollar spot fungus, it is recommended to employ integrated management strategies, switch between fungicide classes after each application, and mix systemic fungicides with a contact fungicide in a single tank. Nozzle type, pressure, and dilution rate are essential for fungicide applications. They must be set correctly for uniform coverage.

If lesions persist despite treatment, it may be necessary to reapply fungicides.

Cultural Control Methods

An integrated approach utilizing chemical and cultural control practices is recommended to effectively treat dollar spot fungus. Adjusting the irrigation schedule, removing dew and guttation fluids by mowing, rolling, whipping, or poling greens early in the morning, avoiding wet foliage, practicing proper mowing techniques, and improving airflow to the turf can all help control and prevent dollar spot infection.

Maintaining a clean and well-kept lawn is also crucial in diminishing the risk of dollar spot fungus. By removing excess debris, avoiding excessive thatch, and aerating the turf, you can create less favorable conditions for the growth and reproduction of Sclerotinia homoeocarpa.

Professional Treatment Services

Professional treatment services may be the answer if you’re still having difficulty managing your dollar spot. Professional lawn treatment services, including regular fertilization and fungicide application, effectively control and prevent dollar spot fungus. Companies such as Davey Tree and TruGreen offer such services and can help you restore your lawn to its former beauty.

By hiring a local lawn care professional, you can ensure that your lawn receives the nutrients necessary to combat dollar spot fungus and maintain a healthy, vibrant appearance. They will be more than happy to inspect the area and provide necessary services for future lawn care.

Don’t hesitate to contact a professional treatment service if you need assistance managing dollar spot fungus.

Summary

In conclusion, recognizing the signs of dollar spot fungus, implementing proper prevention strategies, and applying the appropriate treatment methods are essential to maintaining a healthy, vibrant lawn. By understanding the characteristics and causes of dollar spot, inspecting your lawn for signs of infection, and employing chemical and cultural control methods, you can effectively treat and prevent this common turfgrass disease. Don’t let dollar spot ruin your lawn – take action today and reclaim your beautiful, lush yard!

Frequently Asked Questions

How do you get rid of fungus on a dollar spot?

To eliminate fungus on a dollar spot, fungicides should be applied creatively, and adequate nitrogen fertilizer should be added to the lawn. Additionally, it is important to apply a compost top dressing and remove any excess thatch.

Following these steps will help reduce the severity of the disease.

Will dollar spot fungus go away on its own?

No, the dollar spot fungus will not clear up without proper treatment. Left untreated, it can cause significant damage to your grass and turf, making it necessary to take proactive steps to prevent further spread of the fungus.

Applying a fungicide or following other treatments recommended by a professional lawn care provider is essential for ensuring that your lawn remains healthy and attractive.

What fungicide is used for dollar spot fungus?

The most effective fungicides for dollar spot fungus control are boscalid and flutolanil.

These two fungicides should be applied every two to three weeks to prevent reinfestation.

What is the best product for dollar spot fungus?

The best product for dollar spot fungus is a combination of propiconazole and fludioxonil, which offer an effective solution with a low risk of lawn disease resistance. For additional control, myclobutanil, triadimefon, fenarimol, iprodione, and vinclozolin can also be used as preventive treatments.

Chemical control should only be used as a last resort.

Will dollar spot fungus go away on its own?

Unfortunately, the dollar spot fungus is unlikely to resolve itself without treatment. To prevent further damage and maintain a healthy lawn, it is important to take the appropriate measures to treat the fungus such as applying a fungicide or seeking professional advice.

Failing to do so could result in lasting damage to your grass.

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