What is Dollar Spot Fungus: How to Identify and Control 2025

Ever noticed those mysterious silver dollar-sized spots turning your lush lawn into a polka-dotted mess? You're not alone! Did you know that dollar spot is one of the most common lawn diseases in North America, affecting both residential and golf course turf? I recently helped my neighbor tackle this exact problem - what started as a few small patches quickly spread to cover 30% of his lawn in just two weeks. As a lawn care enthusiast who has battled dollar spot myself, I'll show you exactly how to identify, treat, and prevent this sneaky fungal disease from destroying your turf.

What Is Dollar Spot and How to Identify

Photo Credit: Wikipedia

Dollar spot first caught lawn experts' attention in the 1920s when golf course superintendents noticed mysterious circular patches about the size of a silver dollar damaging their pristine putting greens. Today, we know it as one of the most destructive turf diseases, caused by the fungal pathogen Clarireedia jacksonii (formerly known as Sclerotinia homoeocarpa).

This persistent fungus typically attacks your lawn when temperatures hover between 60-85°F, particularly during periods of high humidity. Think warm days and cool nights – perfect conditions for this unwanted visitor! The fungus spreads through mycelium, tiny thread-like structures that grow between grass blades, especially when morning dew provides the moisture it craves.

What makes dollar spot stand out from other lawn diseases? The telltale signs are distinctive. While brown patch creates large, irregular circles and leaf spot shows up as tiny dark spots on grass blades, dollar spot produces those characteristic silver dollar-sized patches (though they can grow larger in taller grass). Look closely at individual grass blades, and you'll notice something unique – straw-colored lesions with reddish-brown borders that run horizontally across the blade, often creating an hourglass pattern.

The disease thrives under specific conditions that every lawn owner should watch for:

• Drought-stressed turf

• Low nitrogen levels in soil

• Extended periods of leaf wetness (more than 10 hours)

• Poor air circulation

• Excessive thatch buildup

• Morning dew that lingers into afternoon hours

  
  

Understanding these patterns and triggers is crucial because dollar spot often acts as an early warning system – it's telling you something about your lawn's overall health and care routine. The good news? Once you can properly identify dollar spot, you're already halfway to solving the problem.

Want to be completely sure it's dollar spot? Here's my go-to morning test: Walk across your lawn when dew is still present. If you notice white, cobweb-like growths connecting the grass blades (which disappear as the lawn dries), you're likely dealing with active dollar spot infection.

Immediate Treatment Solutions

Here are my three highly recommended fungicides, each with specific benefits and application guidelines:

1. Chlorothalonil-Based Fungicides

Chlorothalonil is a broad-spectrum contact fungicide known for its effectiveness against dollar spot.

• Benefits: Provides rapid control of existing infections and prevents new outbreaks.

• Treatment Time: Visible results can often be seen within two weeks after application.

• How to Apply: Apply using a sprayer to ensure even coverage across the affected areas, following the manufacturer's instructions for dilution and application rates.

• Average Cost: Prices vary depending on the brand and size, ranging from $30 to $100 per gallon.

• Product Link: Eagle 20EW Specialty Fungicide

2. Propiconazole-Based Fungicides

Propiconazole is a systemic fungicide that effectively controls dollar spot.

• Benefits: Offers long-lasting protection and is effective against various turfgrass diseases.

• Treatment Time: Typically applied every 14 to 21 days, depending on disease pressure and environmental conditions.

• How to Apply: Apply using a sprayer, ensuring thorough coverage of the turf. Follow the manufacturer's instructions for dilution and application rates.

• Average Cost: Approximately $50 to $150 per gallon, depending on the brand and concentration.

• Product Link: Propiconazole 14.3 Select Fungicide

3. Azoxystrobin-Based Fungicides

Azoxystrobin is a systemic fungicide known for its broad-spectrum activity.

• Benefits: Provides both preventive and curative control of dollar spot and other turf diseases.

• Treatment Time: Applied every 14 to 28 days, depending on disease pressure and environmental conditions.

• How to Apply: Apply using a sprayer, ensuring even coverage across the affected areas. Adhere to the manufacturer's instructions for dilution and application rates.

• Average Cost: Ranges from $100 to $300 per gallon, depending on the brand and concentration.

• Product Link: Heritage G Fungicide

Natural Treatment Solutions for Dollar Spot

Why go natural? While chemical fungicides might promise quick fixes, natural dollar spot treatments offer peace of mind without compromising effectiveness. I've found that natural solutions not only target the immediate fungal problem but also strengthen your lawn's natural defense systems. You won't have to worry about kids or pets staying off the lawn after treatment, and these eco-friendly options help maintain the delicate balance of beneficial microorganisms in your soil. Plus, unlike chemical treatments that can lead to resistant fungal strains over time, natural remedies work with your lawn's ecosystem to provide sustainable, long-term protection. The best part? Most natural treatments cost significantly less than their chemical counterparts when you consider long-term lawn health and repeated applications.

Compost Tea Treatment

Benefits:

• Enhances soil microbial activity

• Improves grass resistance to disease

• Provides natural nutrients

• Safe for pets and children immediately after application

Application Steps:

1. Brew compost tea (24-hour process) or purchase pre-made solution

2. Dilute at 1:10 ratio with water

3. Apply using backpack sprayer or watering can

4. Treat affected areas plus 2 feet beyond visible symptoms

5. Apply early morning for best absorption

Average Cost:

DIY Brewing Kit: $75-150 (one-time purchase)

Pre-made Solution: $20-30 per gallon (treats ~1,000 sq ft)

Commercial Grade Brewer: $200-400

Neem Oil Solution

Benefits:

• Natural fungicidal properties

• Also prevents other lawn diseases

• Biodegradable

• Won't harm beneficial insects

Application Steps:

1. Mix 2 tablespoons neem oil with 1 gallon of water

2. Add 1 teaspoon of mild liquid soap as emulsifier

3. Spray evenly over affected areas

4. Apply every 14 days until symptoms resolve

5. Best applied in evening or early morning

Average Cost:

Pure Neem Oil (16 oz): $15-25

Annual Treatment Cost: $45-60 for average lawn

Corn Meal Treatment

Benefits:

• Promotes beneficial fungi growth

• Adds organic matter to soil

• Acts as mild fertilizer

• Completely food-safe

Application Steps:

1. Spread corn meal at 20 lbs per 1,000 sq ft

2. Water lightly after application

3. Apply monthly during growing season

4. Can be combined with regular fertilization

Average Cost:

Corn Meal (50 lbs): $25-35

Annual Treatment Cost: $100-150 for average lawn

Baking Soda Solution

Benefits:

• Changes pH to discourage fungal growth

• Readily available

• Extremely cost-effective

• Quick application

Application Steps:

1. Mix 2 tablespoons baking soda per gallon of water

2. Add 1 teaspoon of liquid soap

3. Spray affected areas until thoroughly wet

4. Apply weekly during active infection

5. Best used as preventive treatment

Average Cost:

Baking Soda (5 lbs): $5-10

Annual Treatment Cost: $20-30

Garlic Extract Spray

Benefits:

• Natural antifungal properties

• Deters certain lawn pests

• Long-lasting effect

• No harmful residues

Application Steps:

1. Blend 1 cup garlic cloves with 2 cups water

2. Strain and dilute with 2 gallons water

3. Add 1 tablespoon liquid soap

4. Apply to affected areas twice weekly

5. Reapply after rain

Average Cost:

DIY Solution: $10-15 per batch

Annual Treatment Cost: $60-80

Pro Tips for Natural Treatments:

1. Always test solutions on a small area first

2. Apply in early morning or late evening

3. Maintain consistent treatment schedule

4. Combine with proper cultural practices

5. Keep detailed records of what works best for your lawn

   
   

Preventing Dollar Spot Outbreaks

Prevention is truly the best defense against dollar spot. Through my experience managing both residential lawns and athletic fields, I've discovered that a multi-faceted approach works best. Let's break down the essential strategies that keep your lawn naturally resistant to this persistent fungus.

Best Prevention Practices

The foundation of prevention starts with proper cultural practices. Maintaining the right mowing height (2.5-3 inches for most turf varieties) strengthens your grass's natural defenses. I always recommend watering deeply but infrequently, aiming for 1-1.5 inches per week during early morning hours. This approach promotes deep root growth while minimizing the leaf wetness that dollar spot fungi love. Remember, proper timing is everything - watering before 10 AM allows grass to dry before evening, significantly reducing disease pressure.

Season-Specific Maintenance Tips

Your seasonal approach should adapt as the year progresses. In spring, focus on strengthening your turf with light fertilization and begin a preventive program when soil temperatures consistently reach 55°F. Summer demands extra vigilance - raise your mowing height to reduce stress and monitor humidity levels carefully. Fall is crucial for building winter hardiness through balanced fertilization, while winter becomes your planning period for the upcoming season.

Soil Testing and pH Management

Soil health plays a pivotal role in disease prevention. Maintaining a pH between 6.0-7.0 creates an environment where grass thrives but fungi struggle. I recommend testing your soil every 2-3 years to monitor nutrient levels and make necessary adjustments. If you need to modify pH, do it gradually - add lime to raise pH or sulfur to lower it, always basing applications on actual soil test results.

Grass Varieties with Natural Resistance

When it comes to grass selection, some varieties naturally resist dollar spot better than others. For cool-season lawns, improved Kentucky Bluegrass varieties like Award and Midnight show excellent resistance. In warm-season areas, certain Bermudagrass varieties such as TifTuf and Celebration have proven particularly resilient. Your choice should align with your local climate, soil conditions, and maintenance capabilities.

Wrap-up: Getting rid of dollar spot doesn't have to be overwhelming! By following these treatment methods and prevention strategies, you can restore your lawn's health and keep it looking beautiful year-round. Remember, consistency in maintenance is key to preventing future outbreaks

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About the Author:

A hands-on lawn care enthusiast and entrepreneur who's spent years mastering DIY yard maintenance. When I'm not helping fellow friends, family, and neighbors with their lawn projects, you'll find me tinkering with projects around the house or simply enjoying the peace of watching things grow. My faith and desire to serve others guide me in sharing practical, tested advice that helps people create outdoor spaces they can be proud of.