Troubleshooting Slow-Establishing St. Augustine Sod After Roundup Use

Roundup May Be the Culprit

Glyphosate can persist in soil, especially if tilled in after application. It inhibits root growth in new sod.

Immediate Actions

• Flood the area: Water until runoff, off 1 hour, repeat until 6 inches wet. Do this 2–3x to leach residues.
• Low mowing: Set mower to lowest setting. Mow whenever 1 inch growth appears. Forces energy to roots/runners.
• Sugar application: 1 lb/250 sq ft now. Feeds microbes that break down chemicals and build soil.

Watering Reality Check

1 hour of sprinkler ≈ 1–2 inches soil penetration. Not enough. Use soaker hose or measure with soil probe. Water to 6 inches every 5–7 days (more in heat).

Organic Program for Long-Term

• Sugar spring/fall.
• Compost topdressing ¼ inch annually.
• Mow 2.5 inches spring, 3.5 inches summer.
• Deep, infrequent watering.
• No synthetic fertilizers/pesticides.

Patience with St. Augustine

First year = establishment. Second year = beautiful. "Instant lawn" is a myth. The good pallet will blend in time; the slow one needs root development.

Local Resources

Calloway's Nursery (degreed staff), Howard Garrett's books (dirtdoctor.org), Texas A&M AgriLife Extension.