Dollar spot gets its name from the small, silver-dollar-sized dead spots it creates in turf — but don’t let the size fool you. Left untreated, those individual spots merge into large irregular patches of dead grass that can take over a lawn surprisingly fast. Dollar spot is active in North Texas from late spring through fall, hitting Bermuda especially hard and showing up in Zoysia too. If your lawn has started developing small straw-colored circles with no obvious cause, here’s how to know if it’s dollar spot, and exactly how to stop it. For serious outbreaks, professional lawn disease and fungus control will get it handled right.
What Causes Dollar Spot
Dollar spot is caused by Clarireedia (formerly classified as Sclerotinia homoeocarpa), a fungal pathogen that loves the specific combination of warm days, cool nights, and moisture that the DFW area serves up regularly in spring and early fall. Here’s what feeds an outbreak:
- Nitrogen deficiency: Unlike brown patch, dollar spot actually thrives in low-nitrogen conditions. Turf that’s been under-fertilized is significantly more susceptible. This is one of the few lawn diseases where proper fertilization is part of the cure, not part of the problem.
- Dew and surface moisture: Dollar spot spreads most aggressively when grass stays wet from dew, light rain, or morning irrigation. The fungus moves through wet grass blades, spreading spores from plant to plant.
- Cool nights after warm days: Dollar spot is most aggressive when daytime highs are in the 70s–80s°F and nights drop below 60°F — which is exactly what North Texas spring and fall delivers.
- Drought stress: Turf that’s already stressed from dry conditions is less able to fight off fungal attack. Dollar spot pressure often spikes during stretches of inconsistent rainfall.
How to Identify Dollar Spot
Correct identification is essential before treatment, because dollar spot and other diseases require different fungicide classes to control effectively.
- Small straw-colored circles: Individual spots are typically 2–6 inches in diameter and have a bleached or straw color. They may be perfectly round or slightly irregular.
- The hourglass lesion: This is dollar spot’s most definitive identifier. Pull an individual blade from the edge of an affected spot and look closely. You’ll see a tan or bleached band that crosses the entire width of the blade with reddish-brown borders on each side — creating an hourglass or bowtie shape. No other common lawn disease creates this exact lesion pattern.
- Cottony mycelium in the morning: In humid conditions, dollar spot produces fine, white, cobweb-like strands (mycelium) on the grass surface in the early morning hours before the sun burns them off. If you’re out before 7 AM and see a faint web-like coating on spots in the lawn, that’s active dollar spot fungal growth.
- Merging spots: As the disease progresses, individual dollar-sized circles expand and coalesce into larger irregular patches. Once this happens, the disease is well established and more aggressive treatment is required.
Dollar Spot vs. Brown Patch vs. Heat Stress
Dollar spot spots are smaller and more numerous than brown patch circles, which tend to be larger (often a foot or more across). Dollar spot lesions have that distinctive hourglass pattern on individual blades, while brown patch lesions look different. Heat stress creates uniform dulling rather than individual small spots. If you have many small scattered straw circles rather than one or two large rings, dollar spot is far more likely than brown patch.
Which Grass Types Are Most Vulnerable?
Bermuda is the most common dollar spot victim in North Texas — particularly finer-textured Bermuda varieties. Zoysia can develop it as well, especially in thinning areas or where soil fertility is low. St. Augustine can get dollar spot but is more commonly affected by brown patch and gray leaf spot, so if you have St. Augustine, consider those first before assuming dollar spot.
How to Stop Dollar Spot Before It Spreads
Dollar spot is manageable when caught in the small-spots stage. Here’s the action plan:
- Fertilize with nitrogen. Because dollar spot thrives under low nitrogen, a properly timed fertilizer application improves turf health and disease resistance. Use a slow-release formulation appropriate for the season.
- Irrigate deeply, but less frequently. Deep, infrequent watering encourages deeper roots and allows the surface to dry out between cycles. Light frequent watering keeps surface moisture high — exactly what dollar spot wants.
- Apply fungicide at first signs. Effective fungicide classes for dollar spot include DMI fungicides (propiconazole, myclobutanil), SDHI fungicides, and strobilurins (azoxystrobin). Rotate between fungicide classes if you need repeat applications, since dollar spot is known to develop resistance to specific chemistries with repeated use.
- Mow dry, clean the mower. The fungus spreads via spores, and mower blades carry spores from infected areas to healthy turf. Always mow when dry, and clean the deck after mowing through an affected area.
- Treat a buffer zone. Apply fungicide several feet into apparently healthy turf surrounding each spot, because the disease is already advancing into that area invisibly.
Why Dollar Spot Tends to Come Back
One of the frustrating things about dollar spot is its tendency to recur, especially if the underlying conditions — low nitrogen, surface moisture, susceptible turf — aren’t addressed. A single fungicide application stops the current outbreak, but if soil fertility stays low and irrigation practices don’t change, the next cool spell and dew event will trigger another wave. Long-term control means correcting the conditions that made your lawn vulnerable in the first place. Read about brown patch fungus causes, symptoms, and treatment options to understand how the two diseases differ and why the treatment approach for each isn’t always interchangeable.
Hamann’s Approach to Dollar Spot Control
At Hamann Lawn Care & Weed Control, we’ve been handling North Texas lawn diseases since 2006 — including the full range of dollar spot outbreaks that show up each spring and fall across Arlington and the DFW area. We identify the disease correctly, apply the right fungicide product and rate for your grass type, and help you adjust your lawn care program so dollar spot has a harder time getting a foothold next season. If you’re seeing those telltale small straw circles in your Bermuda or Zoysia, give us a call before they merge into something much bigger.