Grass Won't Grow Over Septic Tank: Soil Testing and Alternative Plantings

Diagnose First

• Soil test: pH, N, P, K. Target pH 6.5. P & K critical for heat/drought tolerance.
• Grass type: Is your seed mix appropriate for your zone?
• Percolation test: Dig 12-15" hole, fill with water. Drains in 1 hour = too dry (water more or amend). Still full tomorrow = too wet (water less or amend).

Planting Over Septic

• No trees—roots damage lines, and tank work removes tree.
• Small raised perennial/annual bed is fine.

Groundcover Alternatives

• Full sun, dry: Sedums (evergreen, drought-tolerant, diverse).
• Under 6 hrs sun: Vinca minor (evergreen, blue flowers, fast).

If All Else Fails

Call county agent for disease/toxin investigation.