Walk across a Bermuda grass lawn in North Texas during May or early June, and you may notice something alarming: scattered circular patches of bleached, straw-colored grass, each roughly the size of a silver dollar, dotting an otherwise green lawn. Unlike brown patch, which creates large irregular rings, or gray leaf spot, which produces hundreds of tiny individual lesions, dollar spot is distinguished by its distinctive small circular spots and the delicate cobweb-like mycelium that bridges between affected blades on dewy mornings. If you are seeing this in your DFW Bermuda lawn, here is how to confirm the diagnosis and understand why this disease strikes when it does.
What Dollar Spot Actually Looks Like
Dollar spot, caused by the fungal pathogen Clarireedia jacksonii (formerly classified as Sclerotinia homoeocarpa), produces some of the most recognizable symptoms of any turfgrass disease. On Bermuda grass, the individual lesion on a single blade shows as a bleached tan or straw-colored band across the blade, typically with a reddish-brown border on either edge of the lesion. These hourglass-shaped lesions are one of the most reliable identification features of dollar spot.
At the patch level, dollar spot creates circular spots ranging from two to six inches in diameter on closely mowed Bermuda lawns. In DFW residential lawns mowed at typical heights of 1.5 to 2 inches, the spots may expand slightly larger. As the disease progresses through May and June, individual spots can coalesce into large irregular blighted areas that lose the circular character of the early infection.
The mycelium is the diagnostic feature that makes dollar spot unmistakable when you catch it early. On mornings when dew is present, step out to your lawn before the sun burns off the moisture and look across the affected area at a low angle. You will see fine, cottony white threads connecting affected blades to nearby healthy ones. This cobweb mycelium disappears within an hour or two as temperatures rise and the dew evaporates, so early morning inspection is essential for this confirmation.
Which Bermuda Varieties Are Most Susceptible in DFW
Not all Bermuda grass varieties carry the same dollar spot risk. Common Bermuda (the seeded variety used on many older DFW residential lawns) shows moderate susceptibility. Among the hybrid Bermudas, Tifway 419 — extremely popular on DFW residential and athletic turf — has moderate to high susceptibility to dollar spot, particularly under low nitrogen conditions. TifTuf and Celebration Bermuda, which have gained significant market share in DFW over the past decade, show somewhat better resistance but are not immune, especially during the prolonged low-nitrogen periods that often precede spring fertilization.
Bermuda lawns that were overseeded with ryegrass the previous winter are also at higher risk during spring green-up. The transition period, when ryegrass is dying out and Bermuda is pushing back through, creates a stressed, open canopy that is vulnerable to dollar spot infection.
Why Low Nitrogen Plus Drought Stress Triggers Dollar Spot in DFW
Dollar spot has a well-established relationship with nitrogen levels — it is a disease of nitrogen-deficient turf. This creates a counterintuitive situation in DFW: even though our summers are hot and humid (conditions that favor many fungal diseases), dollar spot tends to peak in May–June and again in September–October, precisely because these are the shoulder seasons when Bermuda lawns are transitioning between dormancy and peak growth, and many homeowners have not yet applied their first or final nitrogen applications of the season.
Drought stress compounds the nitrogen problem. When a DFW Bermuda lawn goes into moisture stress — which happens surprisingly fast on shallow, compacted clay soils during a dry May — the grass weakens at the crown level. Dollar spot fungus exploits that crown stress to infect the plant. The irony is that many DFW homeowners operate their irrigation systems in water-conservation mode during May before the summer rate schedule kicks in, and that reduced irrigation timing, combined with a late first fertilization, creates the exact conditions dollar spot needs.
Night temperatures above 50°F and below 80°F, combined with daytime highs in the 80s and 90s, represent the sweet spot for dollar spot development. In DFW, this corresponds almost exactly to the April–June and September–October windows. The humid nights — common across the Metroplex due to overnight Gulf moisture intrusion — keep leaf surfaces wet long enough for infection threads to develop.
Seasonal Timing: When Dollar Spot Peaks in North Texas
Based on North Texas weather patterns, dollar spot typically makes its first significant appearance in late April to early May, as soil temperatures climb above 60°F. The primary disease peak runs from mid-May through mid-June. Activity slows dramatically during the most intense DFW summer heat (July–August), when daytime highs consistently exceed 100°F — these temperatures are actually too hot for dollar spot fungus to thrive. The disease resurfaces in September and October as temperatures moderate, often catching homeowners off guard who have stopped monitoring because summer seemed clear.
Why Over-Watering After Dollar Spot Appears Makes It Worse
One of the most damaging mistakes DFW homeowners make when they spot dollar spot is responding by increasing irrigation. The reasoning seems sound — the lawn looks stressed and bleached, so more water should help. In reality, increasing irrigation after dollar spot is confirmed accelerates the spread of the disease significantly.
Dollar spot fungus spreads through water movement. Irrigation droplets splash mycelium and spores from infected blades to adjacent healthy ones. Longer irrigation run times mean extended leaf wetness periods, which give infection threads more time to penetrate the grass blade cuticle. Morning irrigation that leaves blades wet until midday substantially increases infection risk compared to pre-dawn irrigation that allows blades to dry quickly after sunrise.
The correct irrigation adjustment when dollar spot is active is to water deeply and infrequently, preferably completing all irrigation cycles before 10 a.m., and to avoid any late-afternoon or evening watering that leaves the lawn wet overnight. Reducing cycle frequency while increasing run time per cycle keeps soil moisture adequate for the grass while reducing the extended leaf wetness that the fungus needs to spread.
Fungicide Rotation for Dollar Spot in Bermuda
Dollar spot fungus has developed resistance to multiple fungicide classes, making rotation an important part of any treatment program. In North Texas Bermuda lawns, the most effective fungicide classes for dollar spot include DMI (demethylation inhibitor) fungicides such as propiconazole and tebuconazole, SDHI (succinate dehydrogenase inhibitor) fungicides such as boscalid and fluxapyroxad, and QoI (quinone outside inhibitor) fungicides such as azoxystrobin and pyraclostrobin.
Rotating between classes with each application — rather than applying the same active ingredient repeatedly — significantly reduces the risk of resistance development. A typical program might apply a DMI product, then switch to an SDHI on the next application, then move to a QoI combination product. Application intervals for dollar spot control in DFW during active disease pressure are typically 14 to 21 days.
Nitrogen fertilization is the most cost-effective cultural control for dollar spot. Applying 0.5 to 1 pound of soluble nitrogen per 1,000 square feet to a nitrogen-deficient Bermuda lawn will often suppress mild dollar spot activity within two to three weeks without fungicide. However, when disease pressure is high and spots are coalescing, fungicide is necessary to stop active infection while the nitrogen takes effect.
For professional diagnosis and treatment of dollar spot on your DFW Bermuda lawn, visit our lawn disease and fungus control page to learn about our comprehensive fungal disease programs. You can also review our earlier post on purple-tipped grass blades: disease or stress in Texas for additional help distinguishing between disease symptoms and abiotic stress on Bermuda.
Dollar Spot Destroying Your Bermuda Lawn? We Can Stop It.
Hamann Lawn Care & Weed Control has treated dollar spot and other fungal diseases on DFW Bermuda lawns since 2006. We offer accurate diagnosis, fungicide rotation programs, and follow-up monitoring to make sure the disease doesn’t come back.