Grass seed prefers soil with a neutral pH, with the ideal pH for grass seed ranging between 6.0 and 7.0. The soil must remain moist, but not waterlogged, during the first few weeks after planting the seed so the roots can take hold.
To make grass seed grow more quickly and successfully, landscapers often modify the existing soil, either by installing a fresh layer of topsoil or by adding organic matter for extra nutrition. The layer of topsoil should extend at least 6 inches in depth. Landscapers may opt to plant in existing soil instead, adding lime if necessary to alter the soil's pH.
When planting grass seed, landscapers should select a site that follows a grade, which allows water to drain instead of puddle. Add a pre-emergent herbicide to keep weeds away from seedlings.