Dollar Spot vs. Spring Dead Spot in Bermuda Grass: Key Differences in Diagnosis

Bermuda grass is one of the toughest, most heat-tolerant grasses in DFW — until it isn’t. Two diseases hit Bermuda lawns hard in this area, and they look superficially similar from a distance: both create circular areas of dead or bleached turf. But dollar spot and spring dead spot are completely different diseases with different causes, different seasons, different root systems, and completely different treatment strategies. Mixing them up means spending money on the wrong product at the wrong time — and watching your lawn decline while the real problem goes unaddressed. For expert diagnosis and targeted treatment, professional lawn disease and fungus control is the most reliable first step.

Dollar Spot: What It Is and When It Strikes

Dollar spot is caused by Clarireedia jacksonii (formerly classified as Sclerotinia homoeocarpa), a fungal pathogen that infects the blades and leaf sheaths of turfgrass. It gets its name from the size of the damage it creates: roughly silver-dollar-sized spots of bleached, tan grass scattered across the lawn. In Bermuda grass, these spots are typically 2 to 6 inches in diameter when they first appear, though they can merge into larger irregular zones when the disease is running aggressively.

In DFW, dollar spot is a warm-season disease with a very specific weather trigger. It becomes most active in late spring and again in early fall when daytime temperatures are in the 70s and 80s, nights are cool enough for heavy dew, and humidity is high. The disease thrives in the narrow window between “too cool to grow fast” and “too hot and dry for dew.” In a typical DFW year, expect dollar spot pressure from April through June and again from September through October.

The Hourglass Lesion: Dollar Spot’s Signature Clue

The most reliable way to confirm dollar spot is to examine individual grass blades at the margin of the affected area — not in the dead center, which may have already progressed past readable symptoms. Look for:

• Bleached or straw-colored spots on individual blades, roughly centered on the leaf.
• A reddish-brown or tan band crossing the blade at the top and bottom of each lesion, creating a distinctive hourglass shape when you hold the blade up to light.
• Mycelium in early morning: In high humidity, a cottony white web of fungal mycelium may be visible across the lawn surface in early morning before it burns off in the sun. This is one of the clearest field indicators of active dollar spot.
• No root damage: Pull up affected turf. The root system is typically intact and healthy-looking. Dollar spot kills blades from the top down — it is not a root disease.

What Causes Dollar Spot to Spread

Dollar spot thrives in lawns that are low in nitrogen. Under-fertilized Bermuda is the most vulnerable — the disease is sometimes called a “starvation disease” because it attacks weakened, nitrogen-deficient turf almost exclusively. Other contributing factors include:

• Dew and prolonged leaf wetness: The fungal spores need moisture to infect. Morning dew that sits on blades for several hours is a primary driver of spread.
• Mechanical transmission: Dollar spot spores travel easily on mower blades, shoes, and even air movement. A single infected mowing pass can scatter the disease across a large area.
• Overwatering at night: Running irrigation after dark extends the leaf wetness period and dramatically increases infection risk.
• Compacted soil: Poor drainage keeps humidity high at the soil surface, extending the period when conditions favor infection.

Spring Dead Spot: A Completely Different Disease

Spring dead spot is caused by Ophiosphaerella herpotricha (and related species), a root-infecting pathogen that works on an entirely different timeline than dollar spot. The name is somewhat misleading — the damage does not actually occur in spring. The disease infects Bermuda grass roots and crowns during fall and winter, while the lawn is slowing down or dormant. It kills the root and crown tissue underground over the course of the cooler months. The destruction only becomes visible in spring, when the surrounding Bermuda breaks dormancy and greens up — leaving perfectly circular dead patches that stay brown and dormant while everything around them recovers.

This delayed visibility makes spring dead spot one of the most frustrating diseases to deal with. By the time you see the problem, the infection that caused it happened five to six months ago. There is nothing to spray at the moment of discovery — the active infection has long since ended.

How Spring Dead Spot Looks vs. Dollar Spot

The two diseases are easy to separate once you know what to look for:

• Timing: Dollar spot appears during the growing season (spring and fall). Spring dead spot appears exclusively when Bermuda breaks dormancy in March and April, and persists as bleached, dead circles while surrounding turf is actively greening.
• Patch size: Dollar spot creates silver-dollar-sized spots. Spring dead spot circles are much larger — typically 6 inches to several feet in diameter — and are almost perfectly circular.
• Root inspection: This is the definitive test. Pull up turf from inside a spring dead spot circle. The roots are black, rotted, and brittle. Stolons crumble or pull apart with no resistance. The crown tissue is completely destroyed. This is what makes spring dead spot so damaging — recovery requires the lawn to re-colonize from the edges by stolons because there is nothing alive in the center.
• Individual blade lesion: Dollar spot shows the hourglass lesion on individual blades. Spring dead spot shows no blade lesion pattern — the blades are simply dead because the roots that fed them are gone.
• Recovery speed: Dollar spot-affected areas recover quickly with fungicide and nitrogen. Spring dead spot circles may take the entire growing season to fill back in from stolon spread at the edges, and in bad years some circles may not fully recover before dormancy returns.

Why Heavily Fertilized Bermuda Gets Worse Spring Dead Spot

One of the counterintuitive facts about spring dead spot is that heavily fertilized, lush Bermuda is actually more vulnerable, not less. High nitrogen pushes rapid, succulent growth in fall that delays dormancy. Bermuda that enters winter with actively growing tissue has more vulnerable root and crown material for Ophiosphaerella to infect. Heavy thatch also worsens the disease by creating a moist, poorly drained environment at the soil surface where the pathogen thrives. Scalping or de-thatching Bermuda in late summer can reduce spring dead spot pressure in subsequent seasons.

Fungicide Strategy for Each Disease

• Dollar spot: Fungicides containing propiconazole, azoxystrobin, or thiophanate-methyl are effective. Apply at first sign of disease and continue on a 14–28 day interval while conditions remain favorable. Pairing fungicide with a light nitrogen application often gives faster recovery because you are addressing both the infection and the underlying vulnerability simultaneously.
• Spring dead spot: Fungicide must be applied preventively in fall — September through November — before the lawn goes dormant. Products containing propiconazole or thiophanate-methyl applied at 60-day intervals during this window give the best results. There is no effective curative treatment once spring dead spot is visible. In spring, focus on aerating, top-dressing, and light fertilization to help the lawn recover as quickly as possible.

Hamann Lawn Care & Weed Control has been diagnosing and treating Bermuda grass diseases in Arlington and the wider DFW area since 2006. We identify which disease is actually present, apply the right product at the right time, and help you adjust your fall fertilization and irrigation to reduce next year’s pressure. For a related comparison in a different grass, read about brown patch vs. large patch in DFW lawns.