Grow grass over a septic tank by properly sowing the grass seeds and creating future environmental conditions favorable to the growth of grass. Lawn grass species prefer moist, high pH soil, and direct sunlight. Growing grass over a septic tank can be challenging due to the acidic, low-pH soil resulting from sewage runoff into the leach field.
Rake the septic tank area clear of rocks and organic debris using a flexible, metal rake.
Sow the grass seeds over the lawn by evenly distributing the seeds with a spreader. Use 2 or 4 lb. of seed when reseeding a mature lawn or over-seeding a new lawn, respectively.
Sprinkle a 1/12-inch layer of lawn lime over the seeds using a spreader. Lime increases the topsoil's pH balance over time.
Cover the seeds and lime with a 1/2-inch layer of clean compost or peat moss fertilizer. Fertilizer moderates temperature fluctuations, increases moisture absorbency, and adds vital minerals and nutrients.
Water the newly planted seeds once daily for 2 weeks or until new grass growth is visible through the fertilizer.
Trim back adjacent flora to increase direct sunlight on the lawn area using outdoor trimmers.