Replacing Centipede Grass with St. Augustine: Proper Sod Removal and Soil Prep

Laying St. Augustine sod over centipede grass with just a sand layer is a recipe for failure. The old grass will decompose unevenly, create air pockets, and prevent root contact with soil.

Correct Process

1. Remove old sod: Rent a sod cutter (easy to operate, ~$70/day). It slices under roots, leaving clean soil.
2. Amend soil: Incorporate 2-3 inches of compost into top 4-6 inches. St. Augustine needs fertile, well-drained soil.
3. Level and firm: Rake smooth, roll lightly to settle.
4. Lay new sod: Stagger seams like brickwork. Butt edges tightly.
5. Roll and water: Roll for soil contact. Water daily 2 weeks, then taper.

Why Not Sand Over Old Grass?

• Centipede roots create a thatch barrier.
• Sand layer dries out fast—new roots can't reach moisture.
• Decomposing grass creates methane and heat, damaging new roots.
• Uneven settling causes bumps and gaps.

Timing

Best in late spring/early summer when St. Augustine is actively growing. Avoid fall in cooler zones.

Do it right once—sod cutter rental is cheap insurance against a failed lawn.