Centipede Sod Turning Yellow: Iron Deficiency or Fungus?

Three-month-old centipede sod is yellowing despite ample well-water irrigation. Fertilizer made green spots greener but yellow areas spread. The pattern of yellowing holds the clue.

Read the Pattern

• Curved/circular patches suggest biological causes: insects or fungi (e.g., brown patch/Rhizoctonia). If nitrogen worsened it, fungus is likely.
• Straight-edged patches point to abiotic factors: nutrient deficiency, compaction, or chemical injury. Iron deficiency is common in centipede grass on alkaline soils.

Test for Iron Deficiency

Apply liquid iron (chelated iron) to a yellow patch. If it greens up in days, iron is the issue. Caution: Over-application turns grass black and stains concrete, wood, and pavers brown. Follow label rates exactly.

If It's Fungus

Stop night watering. Apply a fungicide labeled for brown patch on centipede grass. Improve air circulation and reduce thatch.

Diagnose by pattern, treat precisely, and avoid blanket applications that waste money and risk damage.