Brown Patch vs. Dollar Spot: How to Identify Lawn Fungus in Texas

Texas lawns, particularly in Keller, Southlake, and Fort Worth, face frequent pressure from fungal diseases. The region’s humid summers, clay-heavy soils, and inconsistent rainfall create the perfect conditions for turf fungi to thrive. Among the most common and destructive are Brown Patch and Dollar Spot.

At first glance, both diseases cause discolored patches that weaken grass and ruin a lawn’s appearance. But while they share some similarities, their causes, patterns, and treatments are different. Misidentifying one for the other can lead to wasted money on the wrong fungicides, continued turf decline, and frustration for homeowners.

This guide will help you:

• Recognize the symptoms of Brown Patch and Dollar Spot

• Understand the conditions that trigger each disease

• Apply the right treatments and cultural practices to restore your lawn’s health

By learning to tell the difference between these two fungal problems, homeowners in North Texas can protect their turf, reduce stress on their lawns, and prevent recurring outbreaks.

For additional turf challenges beyond fungi, check out our Texas lawn pests identification guide.

What Are Brown Patch and Dollar Spot?

Both Brown Patch and Dollar Spot are fungal lawn diseases that weaken turf by attacking grass blades. They thrive in similar environments: humid weather, warm nights, and poorly drained soils, which makes them common problems in Grapevine, Colleyville, and Bedford lawns. While they may look alike at first, their appearance, preferred grass types, and treatment strategies differ significantly. Correct identification is crucial for applying the right solution and preventing long-term turf damage.

For a broader overview of turf health issues, see our guide on drought stress vs. overwatering.

Brown Patch (Rhizoctonia solani)

• Grass types affected: St. Augustine, tall fescue, and Bermuda grass

• Conditions: Thrives in temperatures between 70–90°F with high humidity

• Seasonality: Most active in late spring and fall, especially after periods of rain or overwatering

• Appearance: Creates circular brown or tan patches, sometimes surrounded by a yellow “smoke ring” at the edges

Dollar Spot (Clarireedia jacksonii)

• Grass types affected: Especially common in Bermuda and zoysia lawns

• Conditions: Develops when daytime temperatures are 60–85°F combined with humid nights

• Seasonality: Most active during summer nights, particularly when lawns are mowed short

• Appearance: Small, silver-dollar-sized spots that merge together into larger irregular patches over time

How to Identify Brown Patch in North Texas Lawns

Brown Patch is one of the most common fungal diseases affecting St. Augustine, Bermuda, and tall fescue lawns in Keller, Southlake, and Fort Worth. It thrives during humid periods with warm daytime temperatures and mild nights, especially when lawns are overwatered or soils remain damp.

Symptoms of Brown Patch

• Circular patches ranging from 6 inches to several feet across

• Grass blades turn brown or tan in the center while edges appear yellow

• Leaves often develop lesions with irregular tan centers and dark brown borders

• Turf thins rapidly, creating weak or bare spots across the lawn

Key Visual Difference

• Patches often merge together, forming large, irregular dead zones

• In severe outbreaks, the lawn may appear sunken or matted in affected areas compared to surrounding healthy turf

• Unlike drought stress, brown patch spreads in distinct circles or rings that expand outward

See how our seasonal weed prevention and fertilization programs reduce fungal outbreaks and keep turf healthier.

How to Identify Dollar Spot in North Texas Lawns

Dollar Spot is a fungal disease that often appears in Bermuda and zoysia lawns across Watauga, Westlake, and surrounding areas. Unlike Brown Patch, which creates large dead areas, Dollar Spot produces smaller, scattered spots that gradually expand if left untreated.

Symptoms of Dollar Spot

• Small, round spots, usually the size of a silver dollar

• Patches range from 1 to 6 inches in diameter across the lawn

• Grass blades develop hourglass-shaped lesions with tan centers and reddish-brown borders

• Turf in affected areas feels slightly dry and brittle, even with proper watering

Key Visual Difference

• Spots remain smaller and more scattered compared to Brown Patch

• Lawns appear speckled with distinct circles instead of merging patches

Dollar Spot can spread quickly under the right conditions, especially when lawns are under fertilized or stressed. Our residential lawn care plans help prevent outbreaks by maintaining proper nutrient balance.

Causes and Risk Factors

Brown Patch Triggers

• Overwatering or poor drainage

• High humidity and warm nights

• Excess nitrogen fertilization

Dollar Spot Triggers

• Low nitrogen levels in soil

• Humid conditions with cooler evenings

• Excessive thatch buildup

Shared Risk Factor
Both diseases worsen in clay-heavy North Texas soils. Annual aeration through our commercial lawn care programs helps relieve compaction and improve turf resilience.

Treatment Options for Brown Patch

• Water deeply but infrequently, always in the morning

• Trim surrounding trees and shrubs to improve airflow

• Apply professional fungicides at the first signs of infection

• Aerate compacted soil to reduce conditions favorable to fungus

Our services include Smart Drainage Solutions that reduce standing water and fungal risk.

Treatment Options for Dollar Spot

• Apply a balanced nitrogen fertilizer

• Maintain proper mowing height for your turf type

• Apply fungicides preventively during humid summer months

• Aerate to reduce thatch and improve soil health

Prevent recurrences with our residential lawn care and commercial lawn care programs, which include seasonal fertilization and fungus monitoring.

Preventing Brown Patch and Dollar Spot

• Maintain balanced fertilization year-round

• Adjust watering schedules for each season

• Aerate clay soils annually

• Choose resistant grass varieties where possible

• Promote airflow by pruning trees and shrubs

See how our Southlake lawn care and Trophy Club lawn care programs proactively prevent fungal outbreaks.

When to Call a Lawn Expert

DIY treatments can sometimes help, but persistent fungus often requires professional intervention. Experts can distinguish between fungal diseases, pests, and environmental stresses. Licensed applicators also have access to stronger fungicides for long-term control.

Our team offers tailored lawn care services for communities across North Richland Hills, Grapevine, and surrounding areas to restore and protect lawns.

Conclusion

Brown Patch and Dollar Spot are two of the most common lawn fungi in Texas. Brown Patch thrives in warm, humid conditions with excess nitrogen, while Dollar Spot favors low-nitrogen lawns during cooler, moist nights. Treating one as the other often wastes time and money.

If your lawn shows suspicious circles, spots, or patches, do not wait for it to spread. Conroy’s Lawn and Landscape provides expert diagnosis and treatment programs to keep your turf healthy and attractive year-round.