Start basil seeds in spring when temperatures rise to 60 to 65 degrees Fahrenheit. Basil is sensitive to cold and fails in any frost. The seeds won't germinate in cold, wet soil.
Put basil seeds in sites with full sunshine and quick drainage. Small basil plants thrive between larger plants like tomatoes, cucumbers and beans in the garden but need at least six hours of sun every day. They grow thin and leggy without adequate light.
Dig 4 inches of organic compost into the soil for basil planting. Basil seeds require loose, light and moist soil for germination and fail in tight soil. Add a light application of 10-10-10 fertilizer, but don't over-fertilize. A webpage on the North Carolina State University website notes that too much fertilizer leads to lush basil growth and decreased flavor.
Sow basil seeds directly into the garden. Push the seeds 1 inch deep at every 6 to 10 inches in the row. If you're planting multiple rows, leave 2 to 3 feet between the rows.
Water the basil seeds with 2 inches of water every week for soil moisture. Use a sprinkler setting on the hose to avoid displacing the seeds. Expect germination in four to seven days.