“Nigrospora is most common when lawns are breaking dormancy—March, April, May, and June.”

What It Looks Like, What Causes It, and What You Can (and Can’t) Do About It

By Aaron Shehan – Agronomist & Owner, Burleson Lawn Care

If your St. Augustine lawn in Burleson is suddenly collapsing in patches—especially in spring or early summer—you might be dealing with Nigrospora stolon rot. It’s one of the more aggressive fungal diseases in North Texas and is frequently misdiagnosed as drought, chinch bugs, or even Take-All Root Rot.

Nigrospora attacks the stolons (runners) of St. Augustine, not the roots. It causes rapid turf decline from the top down and is most common in shaded or poorly drained areas.

Nigrospora is most common when lawns are breaking dormancy—March, April, May, and June.

Lawns that go into dormancy under stress—due to drought, shade, or drainage problems—are especially vulnerable when heat and humidity return.

🎥 Real Cases From Local Burleson Lawns

What is Nigrospora Stolon Rot?

Nigrospora stolon rot is a fungal disease that attacks the above-ground stolons of St. Augustine grass. The stolons become blackened, hollow, and brittle, leading to large patches of dead turf that don’t bounce back with water or fertilizer. The disease thrives in moist, humid, shaded environments, and often shows up after overwatering in spring or during extended periods of rain and poor drainage.

It’s not uncommon to see Nigrospora and Take-All Root Rot at the same time, especially in lawns already weakened by stress or poor cultural practices.

Symptoms of Nigrospora in St. Augustine Lawns

  • Large, flattened patches of yellow or brown grass
  • Turf appears matted down and lifeless, with no spring-back
  • Stolons break apart easily and look black, rotted, or hollow
  • No improvement after watering or fertilization
  • Often begins in shady, wet, or compacted areas of the lawn

My Recommended Nigrospora Protocol

There’s no “one product” that fixes Nigrospora. The key is fixing the conditions that allowed it to take hold in the first place. Here’s what I recommend:

  1. Stop All Supplemental Watering
    – Water feeds the fungus. Let the lawn dry out naturally.
  2. Correct Drainage and Shade Problems
    – Thin trees, fix grade issues, and reduce moisture retention.
  3. Power Rake or Verticut
    – Remove dead stolons and thick thatch where the fungus thrives.
  4. Core Aerate
    – Improve oxygen flow to the root zone and break up compaction.
  5. Spot Resod Dead Areas
    – Once conditions improve, new sod may be needed in damaged spots. Do not re-sod too early, or it’ll fail again.

What About Fungicides?

Here’s the truth:

  • There are no fungicides labeled for Nigrospora stolon rot on residential lawns
  • Daconil (chlorothalonil) has shown effectiveness, but it is not labeled for home use
  • Other broad-spectrum fungicides may help slow spread, but they won’t reverse stolon death

That’s why cultural practices—drainage, thatch removal, aeration, and water management—are the most important and effective tools for recovery.

Can Nigrospora and Take-All Be Present Together?

Yes—and it’s actually common.

When lawns are:

  • Overwatered in spring (March–May)
  • Sitting on heavy, poorly drained clay
  • Covered in thatch
  • Struggling with shade or compaction

…it creates a perfect storm for both root-based (Take-All) and stolon-based (Nigrospora) diseases to activate at the same time. Treating just one won’t solve the real problem.

Prevention Tips for Burleson Lawns

  • Avoid watering in spring unless absolutely necessary
  • Aerate your lawn yearly to reduce compaction
  • Power rake each spring to control thatch
  • Mow at the correct height—don’t let the canopy get too dense
  • Watch nitrogen use in hot, humid months
  • Focus on improving drainage and reducing shade

Final Thoughts

Nigrospora stolon rot is fast-moving, hard to diagnose, and rarely talked about—but it’s real. Most of the time, it gets mistaken for something else, and homeowners end up dumping water or fertilizer on it, which only makes the damage worse.

“Our program won’t fix poor cultural practices—but we’ll give you a clear, honest diagnosis and a plan that actually works. No guesswork. No gimmicks.”

📞 Call 1-800-LAWNCARE or visit uglyweeds.com to schedule a turf disease evaluation for your St. Augustine lawn in Burleson, TX.