It is pragmatic to gather best practices on how to grow St. Augustine grass. The same basic rules apply whether you need to know the best way to proceed with sod or grass plugs, or need advice on how to grow St. Augustine grass from seed.
You need about 1/2-inch to 3/4-inch of water for the grass, seasonally adjusted for frequency, in order to avoid patchiness and thinning. Water should cover the top 8 inches of soil. Note that while St. Augustine grass can get through a drought, expect its health to suffer as a result.
Apply 2-5 pounds of nitrogen annually, during active growth periods, in accordance with local ordinances.
Mow the grass to approximately 4-5 inches. When possible, cut no more than one-third of blade length per mowing so that the roots experience as little stress as possible.