Nothing is more frustrating than seeing unsightly brown patches ruin your lush, green lawn—especially after all the effort you put into keeping it healthy. One of the most common causes? Lawn fungus. In Central Ohio, hot, humid, and wet weather creates the perfect conditions for fungal diseases to thrive.
🟤 What Causes Brown Patches in Lawns?
Brown patches can appear suddenly and quickly spread across your yard. While drought, poor mowing practices, or compacted soil can contribute, fungal disease is often the main culprit—especially during late spring through early fall when humidity and moisture levels are high.
🌾 Common Types of Lawn Fungus That Cause Brown Patches
Here are some of the most common fungal diseases we see in the Greater Columbus area:
- Brown Patch (Rhizoctonia solani)
- Appearance: Circular brown patches with a smoky or gray “halo” around the edges.
- When it shows up: Late spring through early fall, especially when nighttime temps stay above 65°F.
- Risk factors: Overwatering, excessive nitrogen, poor air circulation.
- Dollar Spot
- Appearance: Small, silver-dollar-sized tan spots that can expand and merge.
- When it shows up: Cooler nights with heavy dew—spring and early summer.
- Risk factors: Low nitrogen, dry soil surface with humid air.
- Red Thread
- Appearance: Pink or red thread-like strands in the grass.
- When it shows up: Cool, wet conditions, especially in spring and fall.
- Risk factors: Nutrient deficiencies, especially nitrogen.
- Pythium Blight
- Appearance: Greasy, water-soaked patches that turn brown or black quickly.
- When it shows up: Very hot, humid weather with poor drainage.
- Risk factors: Overwatering, poor drainage, thick thatch layers.
- Leaf Spot / Melting Out
- Appearance: Purplish spots on grass blades, eventually causing thinning and dieback.
- When it shows up: Spring and early summer.
- Risk factors: Stress from mowing too short or inconsistent watering.
🛠️ What Can You Do About Lawn Fungus?
Here’s how to protect your lawn and manage fungal issues effectively:
✅ Proper Lawn Care Practices:
- Mow at the correct height: 3.5–4 inches during the growing season.
- Keep mower blades sharp: Dull blades rip grass instead of making clean cuts, which opens the door for fungal infections. A clean cut heals faster and keeps your lawn healthier.
- Water wisely: Early mornings (before 10:00 a.m.), 3–4 times per week during dry spells.
- Avoid over-fertilizing: Too much nitrogen fuels fungal growth.
- Aerate your soil: Reduces compaction and improves drainage.
- Bag clippings during an active outbreak to prevent spreading spores.
🧪 Fungicide Applications: What to Expect
While fungicide treatments can help manage active lawn fungus, it’s important to understand what they can and can’t do.
- Fungicides won’t reverse existing damage. They work by helping contain the spread of the disease—not by repairing the lawn.
- Timing is everything. Lawn fungus often activates overnight, and we can’t always be on-site exactly when it starts. That’s why it’s important to report suspicious brown patches early.
- Fungus lives in the soil. Most types of fungus are always present in your lawn’s environment. Once a lawn experiences fungus, it’s likely to recur in future seasons unless the underlying causes—like excessive moisture, poor mowing habits, or compacted soil—are addressed.
- Our fungicide program helps limit spread. It acts like a barrier to protect the rest of your lawn, giving you a better chance to stop it before it gets worse.
🌿 Long-Term Lawn Health
Fixing the root causes of fungus—such as poor drainage, mowing issues, and nutrient imbalances—is the key to preventing it year after year. Our team at Lawn Doctor of Greater Columbus can help you develop a customized lawn care plan that addresses these issues, reducing the chance of future outbreaks.
👉 Contact us today for a lawn evaluation or to learn more about how our Fungus Control Program can support your lawn through the toughest months of the season.
