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Pathogen: Ophiosphaerella herpotricha, O. korrae (formerly Leptosphaeria korrae) and O. narmari

Also called: SDS, bermudagrass spring dead spot, dead circles in bermudagrass

Spring Dead Spot

Planted in fall, revealed in spring

Spring Dead Spot At-a-Glance

Grass Type Affected

Warm-Season Grasses

Recovers on Its Own?

Yes, Slowly

Is Spraying Worth It?

Sometimes Worth It

Disease Type

Fungal

Active Season

Early Spring

Late Spring & Early Summer

Fall

Damage Potential

Weakens Over Time

Can Be Fatal

Spring Dead Spot Quick Answers

Will my lawn recover on its own?
Yes, slowly
Small patches usually fill in by late summer as healthy bermudagrass runners creep in from the edges. Large patches can take more than one season, and they come back in the same spots next spring unless you change your fall care.
Should I bag my clippings?
No need
The fungus lives in the roots and runners at and below the soil, not in the leaves you mow, so clippings don't spread it. Do rake the dead grass out of the patches in spring so new runners can reach bare soil.
Is it safe for kids and pets?
Yes
The fungus only infects lawn grasses and can't harm people or animals. If you apply a fungicide, keep everyone off the lawn until it has been watered in and the grass has dried.
Should I water more or less?
Less, not more
Soggy soil in fall and spring speeds up the root rot, and extra water won't bring a dead patch back. Water deeply about once a week only when the lawn needs it, and do it early in the morning.
Can it spread to my neighbor's lawn or my garden?
Lawns only
It can only move to other lawn grasses, mainly bermudagrass, mostly in infected sod or in soil carried on mowers and aerators. Garden plants, shrubs and trees can't get it.

What Spring Dead Spot Looks Like

From Standing Height

As the rest of the lawn greens up in spring, sharp-edged circles of dead, bleached, straw-colored grass stay behind. They range from a few inches to several feet across. The patches are often slightly sunken, and they come back in the same spots every spring, usually a little wider. Nearby patches can merge into large irregular shapes or arcs, and as grass or weeds fill a patch’s center over summer, it can take on a ring shape.

Up Close: Blades, Crowns and Roots

The blades show no spots, bands or lesions. They are simply dead, dry, brittle and bleached, because all the damage is underground. Pull up a handful and look at the base. The crowns, the stolons (runners on the surface), the rhizomes (runners under the surface) and the roots are dark brown to black and rotted. Roots are short and brittle, with few or none of the firm white roots healthy bermudagrass has. Dead grass in the patch lifts out with almost no resistance. That contrast, bleached on top and black at the bottom, is the clearest sign of spring dead spot you can see without a microscope.

Signs of the Fungus

You usually can’t see the fungus itself. It grows as fine, dark threads on the outside of roots and runners, but the threads are too small to see without magnification. What you can see is the damage it leaves behind: roots, runners and crowns that have turned black and rotted.

Could It Be Something Else?

Common Lookalikes

Winterkill also leaves bermudagrass dead when the rest of the lawn greens up, often in the same spring. The difference is shape and place. Winterkill follows the landscape. It shows up in low wet spots, shade, north-facing slopes and worn paths, in shapes that wander. Spring dead spot makes sharp circles out in the open lawn and returns to the same spots year after year.

Large Patch hits bermudagrass and zoysiagrass in the same cool weather, including spring green-up, so the timing overlaps. Its active edge often has an orange or yellow border, and the leaves rot at their base and slip off the stem. Spring dead spot patches are evenly bleached, with no colored edge, and the rot is down in the black roots and runners.

Billbugs are weevils whose larvae chew inside the stems and crowns of bermudagrass and zoysiagrass. The dead grass pulls up easily, just like spring dead spot, and Oklahoma State notes the damage is often mistaken for disease or winter injury. The giveaway is inside the stem: billbug-damaged stems are hollowed out and packed with fine, sawdust-like material.

Field Checks Before You Treat

  • Check the timing and shape. Walk the lawn as it greens up in spring. Sharp-edged circles or arcs of dead grass from a few inches to several feet across, out in open turf, point to spring dead spot. Blotchy dead areas that follow low spots, shade or traffic paths point to winterkill.
  • Do the tug test. Grab a handful of dead grass in the patch and pull. If it lifts out with almost no resistance, the roots are gone. That's true for both spring dead spot and billbugs, so go on to the next check.
  • Split a stem at the soil line. Pull a few dead stems and break or slice them open where they meet the soil. Hollow stems packed with sawdust-like material mean billbugs. Solid stems that are black and rotted mean spring dead spot.
  • Wash a plug from the edge. Dig a plug about 3 inches deep where green grass meets dead grass. Swirl it in a bucket of water to rinse off the soil. Black, short, brittle roots and black runners under bleached blades confirm spring dead spot. Firm white roots mean the problem lies elsewhere.
  • Look at the patch edge. On a patch that's still expanding, check the border grass. An orange or yellow fringe, with leaves that slide off a rotted base, points to large patch instead.
  • Map it and check next spring. Photograph or sketch where the patches are this spring. If they slowly fill in over summer and then reappear in the same spots, a little wider, next spring, that pattern is spring dead spot.

Grasses at Risk

Host Grasses

Which Grasses Suffer Most

Bermudagrass is the main host, and hybrid bermudagrasses suffer more than common types. Resistance follows cold hardiness: varieties that handle winter well survive the root damage better. Kansas State lists Latitude 36, Midiron, Midlawn, Northbridge and Patriot (planted as sod or sprigs) and Yukon and Riviera (planted from seed) as less susceptible. No variety is immune. Check the National Turfgrass Evaluation Program for cold-tolerance ratings before replanting. Zoysiagrass is an occasional host, with Meyer and El Toro named by NC State, but Oklahoma State finds it rarely affected. Buffalograss is rarely affected. Cool-season grasses such as Kentucky Bluegrass don’t get spring dead spot, though one of the same fungi causes Necrotic Ring Spot on them.

Why It Shows Up

Conditions That Trigger It

Spring dead spot is a fall disease that you only see in spring, and winter cold finishes the job. The fungus starts attacking roots and runners when soil temperature drops below about 70°F in fall, and it keeps working until soil falls below 50°F. It picks up again briefly in spring as soil warms, and stops once soil climbs back above 70°F. The fungus doesn’t usually kill the grass directly. It rots the roots and runners so badly that the plants can’t survive freezing weather. That’s why damage is worst after very cold winters and at the northern edge of where bermudagrass grows.

Care and site factors that raise the risk:

  • Late nitrogen. Fertilizer in late summer or fall keeps bermudagrass growing when it should be hardening off for winter, which makes it far more likely to freeze. This is the single biggest factor you control.
  • Heavy nitrogen overall. Lush, heavily fed lawns get the most disease. Auburn notes that low-maintenance bermudagrass lawns usually have few problems.
  • Thick thatch. A thatch layer over ½ inch lifts crowns and roots up into the thatch, where they are more exposed to cold and where the fungus thrives.
  • Compaction and poor drainage. Hard or waterlogged soil keeps roots shallow and weak, and wet soil in fall favors the fungus.
  • Overwatering. Keeping the soil soggy in fall and spring does the same thing as poor drainage.
  • High soil pH. Soil above about pH 7 is linked to more disease.
  • Low potassium. Potassium deficiency is listed by NC State as a factor that encourages the disease.
  • Lawn age. The disease usually first appears 3 to 5 years after a bermudagrass lawn is planted, once the fungus has built up in the soil.
  • Grass variety. Hybrid bermudagrasses and varieties with poor cold tolerance suffer the most.

How It Survives and Spreads

The fungus survives from year to year inside the roots, runners and crowns it has already infected. That’s why patches return to the exact same spots each spring. In fall, as the soil cools, the fungus grows out along roots, rhizomes (underground runners) and stolons (above-ground runners) and rots them. The lawn goes dormant looking normal. Over winter, the damaged plants die from the rot and from cold they can no longer tolerate. In spring, the healthy grass greens up and the dead circles appear. In summer, the fungus goes quiet and healthy runners slowly creep back into the patches. Each year the patches tend to grow a few inches wider.

The fungi that cause spring dead spot rarely spread by spores. They mostly move in infected sod or sprigs, and in soil and bits of infected plants carried on aerators, dethatchers, mowers and shoes.

Where It Hits Hardest: Regional Notes

Spring dead spot is the most damaging disease of bermudagrass lawns in the transition zone and the northern part of bermudagrass country, including Oklahoma, Kansas, Missouri, Kentucky, Tennessee, Virginia, North Carolina and the upper parts of South Carolina and Georgia. Cold winters there turn weakened roots into dead patches. It also shows up in bermudagrass lawns in California. In the Deep South and along the Gulf Coast, milder winters mean less freeze damage, so the disease is usually less severe. It isn’t a problem in northern lawns of cool-season grasses, although one of the same fungi causes Necrotic Ring Spot on Kentucky Bluegrass.

Spring Dead Spot Diagnostic Profile

Check what you see against the full set of signs. The more that match, the more likely this is your problem.

What You’ll See

Symptom Color

Tan or Straw

Yellow

Brown

White or Gray

Black or Dark

Visible Signs

None Usually Visible

Lawn Pattern

Circular Patches

Rings or Frog-Eyes

Irregular Patches

Patch Size

2 to 6 Inches

6 to 12 Inches

1 to 3 Feet

Over 3 Feet

Blade Symptoms

Rotted Leaf Base or Crown

Rotted Roots

When and Where

Weather Triggers

Cool & Wet

Wet or Poorly Drained Soil

Where in the Lawn

Low or Wet Spots

Compacted or High-Traffic Areas

Open, Sunny Lawn

Controlling Spring Dead Spot

  • Stop nitrogen about 6 weeks before dormancy. Late feeding pushes soft new growth just as the grass should be storing energy for winter. Extension cutoffs include early August in Kansas, August 15 in upstate South Carolina, September 1 on the South Carolina coast and September 15 in Oklahoma. Use your state’s date.
  • Keep each feeding light. Apply no more than 1 lb of actual nitrogen per 1,000 sq ft at a time, and keep the yearly total moderate. Kansas State links more than 4 to 5 lb per 1,000 sq ft per year to worse disease. Heavily fed bermudagrass gets the worst disease.
  • Choose the nitrogen source only where the evidence is clear. In the Plains and Midwest, where O. herpotricha is the main fungus, ammonium sulfate helps suppress it. In the East, the research is split on whether ammonium or nitrate forms help, so focus on timing and rate instead.
  • Keep soil pH out of the high range. Get a soil test and don’t lime beyond what it calls for. Clemson and Auburn suggest pH 5.8 to 6.2, and pH above 7 is linked to more disease.
  • Keep potassium adequate. Follow your soil test. Extra potash in fall didn’t reduce the disease in NC State’s trials, so more isn’t better.
  • Dethatch when thatch passes ½ inch. Do it in late spring or early summer, when the bermudagrass is growing strongly and can heal (Clemson suggests May). Thick thatch holds the fungus and leaves crowns exposed to cold.
  • Core aerate the patches in summer. Aeration breaks up the dead mat and loosens compacted soil so runners can root into the bare spots. NC State recommends aerating badly affected areas at least three times a year, spread through summer while bermudagrass is growing fast.
  • Water deeply, not often, and early. About 1 inch once a week on clay soil, only when the lawn needs it, before sunrise. Soggy fall and spring soil feeds the fungus. Fix spots where water stands.
  • Raise the mower a notch in late summer or early fall. UC IPM recommends it to reduce stress before dormancy. Taller grass makes more food to store for winter, which helps weakened plants survive the cold.
  • Skip crabgrass preventers on the patches. Dinitroaniline preemergence herbicides (prodiamine, pendimethalin, oryzalin) stop runners from rooting, which keeps the patches bare longer. Avoid them on lawns with a spring dead spot history.
  • Clean your equipment. Hose soil and debris off aerators, dethatchers and mower decks after working the patches so you don’t carry infected bits to clean parts of the lawn.

Sometimes worth it: only in fall, and only on a lawn with a confirmed, repeat history of serious spring dead spot. A spring spray does nothing, because the grass in the patches is already dead.

Fungicides protect healthy roots before the fungus reaches them. Make the first application early in fall, as soil temperature falls through the 70s°F (NC State’s window is 60 to 80°F soil), about a month before the lawn goes dormant. Repeat as the label directs, usually 2 to 4 weeks later. The fungus lives in the roots, not on the leaves, so water the product in right away with about ½ inch of water. Map your patches in spring and treat those areas plus a border around them, rather than the whole lawn.

Active ingredientFRAC groupNC State rating (+ to ++++)Notes
Propiconazole3+++The most useful homeowner option.
Azoxystrobin + propiconazole11 + 3+++Two modes of action in one product.
Azoxystrobin11+Weak on its own against spring dead spot.
Myclobutanil3+Common in home products, but weak here.
Thiophanate-methyl1+Weak, and the fungus becomes resistant with repeated use. Alternate with group 3 or 11.
Isofetamid, cyclobutrifluram, pydiflumetofen, mefentrifluconazole7 or 3++++Top-rated, but sold to professionals; several are not labeled for home lawns. Ask a lawn care company.

Even the best products reduce spring dead spot rather than eliminate it, and you may need to treat every fall until patches stop appearing. In Oklahoma and Kansas, where trials have given erratic results, Extension does not recommend fungicides for home lawns at all. Fix the fall nitrogen first.

Recovery and Repair

Dead crowns inside a patch don’t regrow, so recovery only comes from healthy runners creeping in from the edges. Small patches usually fill in by late summer. Patches more than about a foot across can take several growing seasons.

To speed it up, rake the dead grass out of the patches in late spring so runners can touch bare soil and root. Bag that debris for yard-waste pickup or the trash. Don’t compost it, because the fungus lives in it. Core aerate the patches during summer, feed lightly while the grass is growing (stopping by your fall cutoff date), water when dry, and spot-treat weeds that move into the bare areas. Avoid crabgrass preventers on the patches.

For large patches that won’t close, plug, sprig or sod them in early summer, once bermudagrass is growing fast. Use a cold-hardy variety if you’re bringing in new grass. Don’t patch with ryegrass or tall fescue seed. It competes with the bermudagrass runners you’re relying on and slows recovery.

When to Call a Pro

Send a sample to your state’s Extension plant diagnostic lab if you can’t tell spring dead spot from large patch, billbugs or winterkill after the checks above, or if patches keep growing every year even after you’ve fixed your fall fertilizing. Dig a plug about 4 inches wide and 3 inches deep from the edge of a patch, half dying grass and half healthy, and leave the soil on the roots. A plug from the dead center won’t work, because there’s nothing alive left to test. Wrap the soil in plastic, leave the grass exposed, and ship early in the week. Call a lawn care professional if your history justifies fungicides, since the strongest products are professional-only.

Frequently Asked Questions

These answers are synthesized from plant pathology research and diagnostic guidance published by university extension services and plant disease clinics.

Can I spray a fungicide now to fix the dead patches?

No. By the time the patches show up in spring, the grass in them is already dead, and no fungicide can revive it. Fungicides only work as protection in early fall, before the fungus reaches the roots. For now, help the patches fill in, and mark where they are for fall.

Why did this show up when my lawn looked fine for years?

The fungus takes time to build up. Spring dead spot typically first appears 3 to 5 years after a bermudagrass lawn is planted, as the fungus multiplies in the soil and thatch accumulates. A cold winter after years of buildup often makes it appear all at once.

Why are the patches staying bare even though I treated for crabgrass?

The crabgrass preventer may be the reason. The most common preemergence herbicides (dinitroaniline types such as prodiamine and pendimethalin) stop roots from forming. That blocks crabgrass, but it also stops bermudagrass runners from rooting as they try to cross the bare patches. Skip these products on lawns with spring dead spot and spot-treat weeds after they appear instead.

Will spring dead spot eventually go away on its own?

Don’t count on it. Kansas State has seen the disease ease off after 7 to 10 years in some lawns, but NC State reports it does not fade as a lawn ages. Without changes to fall care, patches usually return to the same spots and widen each year.

Scientific Authority

This profile is built on plant pathology research and diagnostic guidance from university extension services and plant disease clinics. We prioritize accurate identification and cultural control first, recommending fungicides only where research shows they are justified, and naming them by active ingredient rather than brand.

Primary Resources