Recurring St. Augustine Brown Patch: Fungus, Bird Seed, or Fertilizer?

5×3 ft Spot Dies Year After Year

St. Augustine, full sun, watered, fertilized. Sod replaced 2 months ago; now brown again. Same spot last year.

Suspect 1: Brown Patch Fungus

• Doesn't self-cure; needs fungicide or baking soda (saturate soil).
• Usually spreads, but can persist in favorable microclimate.

Suspect 2: Bird Feeder Toxicity

• Black oil sunflower hulls = allelopathic (toxic to plants).
• Buildup over years poisons soil.
• If feeder there: remove, drench soil heavily, or replace soil.

Suspect 3: Fertilizer Hot Spot

• Past over-application created salt buildup.
• Drench repeatedly to leach; or replace soil.
• No more fertilizer on that spot.

Action Plan

1. Check for bird feeder above spot.
2. Soil test (pH, salts, nutrients).
3. Treat with fungicide or baking soda drench.
4. If feeder/hull buildup: remove soil 6–8 in, replace, resod.
5. Consult local nurseryman for area-specific issues.

Organic Alternative

• Sugar program (1 lb/250–300 sq ft, spring/fall) builds soil health.
• Fertilizer kills microbes; sugar feeds them.
• Weeds don't thrive in rich soil.

Bottom Line

Recurring spot = persistent soil issue. Fungus, bird seed toxins, or fertilizer salts. Soil test + history check reveals cause. Fix the soil, not just the grass.