Quick Answer: When Should You Treat for Spring Dead Spot?
Treat bermuda in fall, while soil at 2 inches falls from 70°F to 55°F. Your schedule opens the task once soil has been falling at 70°F or below for 5 days and closes it once soil holds below 55°F. Make one or two applications, 30 days apart with a propiconazole product. Spraying in spring does not work. Fix the cultural causes first: no nitrogen in the 6 weeks before dormancy, a soil pH of 5.8 to 6.2, and less thatch. The sources disagree on where in the 55-70°F window to spray: NC State and Purdue start at 70°F, and newer research from Virginia Tech and the University of Arkansas points to the cooler end.
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Spring dead spot shows up as bleached, dead circles in a bermuda lawn just as the rest of it greens up. It looks like a spring problem, but a spray at that point comes too late. By then the roots in those circles were infected the previous fall and killed over the winter.
Prevention happens in fall. A fungicide has to be in the root zone as the soil cools, and a lawn has to go into winter without the late nitrogen, high pH and thick thatch that make the disease worse.
This guide covers what the disease is, the fall soil window and why the sources disagree on it, where spring dead spot is worst, how many applications to make, why spring spraying fails, the cultural steps that come first, and the two propiconazole products that fit a homeowner program.
What Spring Dead Spot Is and Why Soil Temperature Times It
Spring dead spot is a root disease of bermuda caused by fungi in the genus Ophiosphaerella. Purdue Extension calls it the most serious disease of bermudagrass. The University of Arkansas says most warm-season grasses are susceptible but bermuda is the most susceptible species, and NC State Extension adds that it can occur on some zoysia varieties, such as 'Meyer' and 'El Toro'. Texas A&M AgriLife describes it as a crown, root and stolon rot of dormant grass.
The patches are circular, from 6 inches to several feet across (NC State), and they come back in the same places each spring and grow larger. Alabama Cooperative Extension says they become less noticeable 2 to 3 months after spring green-up, and the University of Missouri notes that weeds can invade the patches before bermuda fills them back in.
Severity depends on two things, according to Purdue: how much of the root system was infected in the fall, and how cold the following winter is. Infection weakens the roots in fall, and sustained cold then kills them. Purdue says the fungi infect when soils are moist and between 50 and 70°F. NC State Extension, citing Oklahoma State research, says the pathogens are most active between 75 and 60°F, with optimal infection at 65°F. That is the stretch of fall a fungicide has to cover, and soil temperature shows when it starts.
The Trigger: Soil Falling From 70°F to 55°F
The sources all time the spray to cooling fall soil. Where in that cooling to spray is the open question, and the newer research sits at the cooler end.
| Source | Soil temperature | Depth | Rule |
|---|---|---|---|
| NC State Turf Pathology (2020) | First application as soil drops to 70°F | Not stated | Repeat 21 to 28 days later until soil falls below 55°F |
| Purdue BP-120 (2016) | Start as soil approaches 70°F | 2 inches | One or two sprays in fall, before dormancy |
| NC State TurfFiles (2019) | Most effective between 60 and 80°F | Not stated | Range |
| UGA (2024) | One application between 60 and 75°F | Not stated | Second 4 to 6 weeks later under high pressure |
| University of Arkansas FSA7584 (2026) | Consistently between 55 and 65°F | Not stated | One may be adequate; second three to four weeks later |
| Virginia Tech, Crop Science (2025) | Five-day average of 55-64°F, best near 55°F | 0 to 4 inches | One to two times in autumn |
Only Purdue (2 inches) and Virginia Tech (0 to 4 inches) state a depth. SoilTemps reads soil at 2 inches.
The older rule comes from NC State Turf Pathology: apply when soil temperatures drop to 70°F in the fall, then again 21 to 28 days later until soil falls below 55°F. Purdue Extension gives the same 70°F start and calls its own evidence anecdotal. NC State TurfFiles and University of Georgia Extension give wider ranges (60 to 80°F; 60 to 75°F).
The newer work points lower. A 2025 study by Virginia Tech researchers (Hutchens, Booth, Goatley, Roberson and McCall, published in Crop Science and summarized by GCM) found the best control when the five-day average soil temperature at 0 to 4 inches was 55-64°F, and applications near 55°F gave the best chance of control. The University of Arkansas fact sheet (2026) puts the best time at soil consistently between 55 and 65°F.
Your schedule opens the task when 2-inch soil has been falling at 70°F or below for 5 days and keeps it open until soil holds below 55°F. If you make one application, make it at the cooler end of that window, once your reading is between 55 and 65°F, as Virginia Tech and Arkansas advise. If you make two, make the first when the task opens and the second 30 days later, before soil falls below 55°F.
The window runs from 70°F to 55°F because it covers both rules: NC State's start at 70°F and its stop below 55°F, with the Virginia Tech and Arkansas ranges inside it.
Where Spring Dead Spot Occurs
The sources agree that spring dead spot is worst where bermuda sits near the cold edge of its range, and worse after hard winters.
- Purdue Extension says it is a greater concern in the northern areas of the transition zone, where the climate is less suited to warm-season grasses.
- NC State Extension says it is most severe in the northern range of bermudagrass adaptation and usually more severe after extremely cold winters.
- The University of Missouri calls it a destructive disease of bermuda throughout the northern range of its adaptation in the United States.
Your schedule decides whether to show the task from your area's normal summer and winter temperatures and its climate type. It shows the task where winters are cold enough for bermuda to go fully dormant but not so cold that bermuda lawns are uncommon, and where summers are warm enough for bermuda lawns. It leaves out the hot deserts and cool-summer climates, and in the Mountain West it keeps the task only in the high desert of Arizona and New Mexico, where bermuda goes dormant. Your soil readings then set when the task opens and closes.
Transition Zone
This is where the disease does the most damage. NC State's fall timing advice is written for bermuda and zoysia in the transition zone. The University of Arkansas calls spring dead spot the most problematic disease of bermuda lawns in Arkansas.
Your schedule shows this task whether your city defaults to cool-season or warm-season grass, so a bermuda lawn in a city that defaults to tall fescue still gets it. If your own lawn is tall fescue, skip it.
At the northern edge, the sources are less hopeful about fungicides. Purdue warns that root infection followed by long cold spells, common in the Midwest, can cause severe outbreaks even on the most cold-tolerant bermuda varieties. The University of Missouri says fungicides give erratic control and are not currently recommended for spring dead spot in the Midwest. If you are in that region, put the cultural steps below first and treat only the areas that had patches.
The South
In Georgia and Alabama, the sources describe the disease as worst in the northern part of the state. University of Georgia Extension says its prevalence and severity are particularly high in the northern part of Georgia. Alabama Cooperative Extension says it is most common in the northern half of Alabama, where hybrid bermuda is less well adapted, but damage may be seen statewide after an unusually cold winter. Clemson says symptoms are worse after cold, wet winters and milder after warm, dry ones.
South Carolina times its applications by the calendar: Clemson starts about one month before the lawn goes dormant, around October 1, with a second in mid-October and a third at the end of October.
If your schedule does not show the spring dead spot task but you have a bermuda lawn with a history of spring dead spot, use the rule by hand: treat in fall as your 2-inch soil falls from 70°F to 55°F, and map the patches in spring so you know where to treat.
The Second Application
Most of the sources allow one application and suggest two where the disease has been bad. They space them differently:
| Source | Applications and spacing |
|---|---|
| NC State Turf Pathology | Second 21 to 28 days after the first, until soil falls below 55°F |
| University of Arkansas | One may be adequate; a second often three to four weeks later |
| University of Georgia Extension | Two when pressure is high, the second 4 to 6 weeks later |
| Clemson HGIC | Three, around October 1, mid-October and the end of October, alternating active ingredients |
| Alabama Cooperative Extension | A single application often works as well as two |
| Purdue Extension | One or two sprays in fall, before dormancy |
The product label has the last word. Both propiconazole products in this guide set 30 days between spring dead spot applications and allow up to three, so with either one the second application comes 30 days after the first. Clemson's roughly two-week spacing alternates active ingredients, so no one product is repeated that soon.
Map first: in spring, mark where the dead circles were. NC State and Alabama both say to treat the mapped areas in fall instead of the whole lawn.
One application: when your 2-inch reading is between 55 and 65°F, before bermuda goes dormant.
Two applications: the first when your schedule opens the task, the second 30 days later, before soil falls below 55°F.
Water it in right away: the fungicide has to reach the roots. NC State asks for at least 1/8 inch of water immediately after application, and Arkansas asks for 0.2 to 0.5 inch. Put down at least a quarter inch.
Why Spring Spraying Does Not Work
The University of Arkansas puts it directly: only fall fungicide applications have been proven effective, and spring fungicide applications are not effective. NC State Extension says fungicides for spring dead spot must be applied preventatively in the fall. By the time the circles appear, the roots inside them died over the winter, and a fungicide cannot bring them back.
Use the spring to plan the fall instead. Map the patches (NC State says this also cuts what you spend on fungicide), keep weeds out of them, and let the bermuda grow back in.
Cultural Controls Before Any Fungicide
Purdue says fungicides often fail to give satisfactory control, and Alabama calls their effectiveness erratic and says they work best combined with good maintenance over several years. Put these in place first.
Step 1: Stop Late-Season Nitrogen
NC State Extension says not to apply nitrogen within 6 weeks of winter dormancy, and never more than 1 lb of nitrogen per 1,000 sq ft in one application. University of Georgia Extension allows no more than ½ lb of nitrogen per 1,000 sq ft after mid-September. Clemson stops nitrogen by August 15 in the Upstate and September 1 along the coast. Purdue says reports show the disease is worse after late summer nitrogen. When you do feed, Alabama says acidifying nitrogen sources such as ammonium sulfate have been shown to reduce spring dead spot. Time your feedings with the warm-season fertilization schedule and skip the fall winterizer on bermuda that has had spring dead spot.
Step 2: Keep Soil pH Between 5.8 and 6.2
Clemson, University of Georgia Extension and Alabama Cooperative Extension all say to keep soil pH between 5.8 and 6.2. Clemson gives the reason: a higher pH has been linked to more spring dead spot. Georgia and Alabama suggest acid-forming fertilizers where the soil is near neutral or alkaline. NC State says the effect of pH on the disease is not yet clear, so test the soil first and adjust only if it is above that range.
Step 3: Cut Thatch and Compaction in Summer
NC State recommends aggressive aerification and vertical mowing, and says badly affected areas should be hollow-tine aerified at least three times a year during the summer, when bermuda grows fastest. Clemson dethatches in May. University of Georgia Extension lists compaction, thatch over ½ inch and poor drainage among the conditions that cut root growth. For bermuda aeration dates, see the aeration timing guide.
Step 4: Skip Dinitroaniline Pre-Emergents on Affected Areas
NC State Extension warns that dinitroaniline herbicides, commonly used as pre-emergents for annual grasses, can slow bermuda's recovery from spring dead spot and should not be used in sites with a history of the disease. South Dakota State University Extension lists prodiamine and pendimethalin as dinitroanilines. Leave the mapped patches out when you spread your spring pre-emergent.
Step 5: Add Potassium Only If a Soil Test Says So
The sources disagree here. NC State found that fall potassium had no effect on the disease in its research, and Purdue says potassium nutrition does not appear to influence severity. University of Georgia Extension says fall potassium totaling 1 lb of K2O per 1,000 sq ft can help, based on a soil test, and Clemson keeps potassium at the upper end of the sufficient range. Test the soil, and add potassium only if it comes back low.
When You Replant
No bermuda is immune. The University of Missouri lists 'Midlawn' and 'Patriot' as resistant vegetative varieties and the seeded 'Yukon' and 'Riviera' as moderately resistant. Purdue says winter-hardy varieties are reportedly less prone to damage, but shows spring dead spot on 'Patriot' in West Lafayette, Indiana.
Stop nitrogen 6 weeks before dormancy, bring the soil pH to 5.8-6.2 if a test shows it is higher, aerate and dethatch in summer, and keep dinitroaniline pre-emergents off the patches. Alabama says low-maintenance bermuda lawns usually have few issues with spring dead spot.
What you need
- Granules, for a spreader: Andersons Prophesy propiconazole
- Liquid, needs a pump sprayer: Select Source propiconazole 14.3
Fungicides for Spring Dead Spot
A fall fungicide comes after those steps, and only on a lawn that has had spring dead spot before. Spray the patches you mapped. Purdue says efforts to limit this disease often have inconsistent results, and Alabama calls fungicide results erratic and says fungicides work best alongside good maintenance kept up over several years. Keep the cultural steps going in every year you spray.
Clemson Cooperative Extension rates the home lawn fungicides for spring dead spot. Propiconazole products rate Good. Myclobutanil and thiophanate-methyl products rate Fair to Good, and Clemson warns that the fungus can become resistant to thiophanate-methyl used alone. The University of Arkansas recommends isofetamid, penthiopyrad and cyclobutrifluram, none of which appear in Clemson's home lawn ratings.
Azoxystrobin (Scotts DiseaseEx) lists spring dead spot on its label, and NC State includes it in its fungicide table. Clemson's ratings do not rate an azoxystrobin-only product for spring dead spot, so this guide uses propiconazole. The lawn disease by temperature guide covers fungicide groups and why to rotate them.
Two cautions apply to bermuda. Both propiconazole labels warn that bermudagrass can be sensitive to the product and cap the amount applied every 30 days. Clemson adds that propiconazole in the fall may slightly delay green-up the next spring.
1. Propiconazole Granules (Best for Spreading on Mapped Patches)
Common Brand Name: The Andersons Prophesy
The label lists spring dead spot at 5 lb per 1,000 sq ft every 30 days: one to three applications, in September or October for a single application, starting in August for more than one. It also says not to exceed 5 lb per 1,000 sq ft every 30 days on any bermuda. For soil-borne diseases the label allows watering in after application, which the sources require for this disease. Keep people and pets off until the dust has settled.
Best Used For: Homeowners treating mapped patches with a spreader.
The Andersons Prophesy Propiconazole Granular Fungicide (25 lb, 10,000 sq ft)
Propiconazole granules whose label lists spring dead spot at 5 lb per 1,000 sq ft every 30 days, one to three applications in fall. Do not exceed 5 lb per 1,000 sq ft every 30 days on bermuda. Water in right after spreading so it reaches the roots.
2. Propiconazole Liquid (Best for Larger Areas)
Common Brand Name: Select Source Propiconazole 14.3
The label lists spring dead spot at 4 fl oz per 1,000 sq ft every 30 days: one to three applications, in September or October for one, beginning in August for more. It says not to exceed 4 fl oz per 1,000 sq ft every 30 days on any bermuda. For soil-borne diseases it can be watered in after application. Purdue notes that labels often suggest a spray volume of 2 to 4 gallons per 1,000 sq ft or a quarter inch of irrigation afterward, so you need a pump sprayer. Stay off the lawn until the spray has dried.
Best Used For: Larger bermuda lawns and owners who already have a sprayer.
Select Source Propiconazole 14.3 Fungicide (pint concentrate)
Propiconazole concentrate whose label lists spring dead spot at 4 fl oz per 1,000 sq ft every 30 days, one to three fall applications. Do not exceed 4 fl oz per 1,000 sq ft every 30 days on bermuda. Spray, then water in so it reaches the roots.
Common Mistakes
Spraying in spring. The dead circles were infected the previous fall. Arkansas says spring applications are not effective. Map them and wait for fall.
Leaving the fungicide on the leaves. This is a root disease. Water it in with at least a quarter inch right after you apply.
Two applications too close together. Both propiconazole labels set 30 days between spring dead spot applications and limit how much bermuda can take in that time.
Fall nitrogen and winterizers. Late nitrogen makes the disease worse. Stop 6 weeks before dormancy.
A crabgrass preventer on last year's patches. Prodiamine and pendimethalin are dinitroanilines, which NC State says slow recovery. Leave the patches out.
Treating a fescue lawn. The task appears on cool-season schedules in the transition zone for bermuda lawns. If your lawn is tall fescue, it is not for you.
Track Your Local Soil Temperatures Today
The 70°F-to-55°F window moves with your own soil, and it shifts from one fall to the next. A date borrowed from another state can put the fungicide down before the fungus is active or after bermuda has gone dormant.
SoilTemps.com reads 2-inch soil at more than 300 USDA SCAN and NOAA USCRN stations; a city far from a station gets a Modeled reading. Where the task applies, your lawn care schedule opens the spring dead spot task as fall soil falls through 70°F and closes it once the soil stays below 55°F, the span for the first and second applications.
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