Basil is among the easiest herbs to grow and will produce a harvest from late spring until fall. In general, the more that is harvested or pinched off, the more basil one plant will produce. Typically, one or two plants are grown for harvesting. Alternatively, basil can be grown as ornamental plants and make an excellent addition along borders and as accent plants in the home garden. While basil can be planted from seed, they are more easily grown if purchased as small established plants.
Decide which kind of basil plants you want to grow. For example, "Lettuce-leaf" basil is used in salads and "Thyrsiflora" basil is used in Thai dishes. "Camphor" basil is used as a tea to help alleviate cold and stomachache symptoms. "Purple Ruffle" basil has maroon colored leaves and lavender flowers and is typically grown as an ornamental plant, but can be used to flavor vinegar as well.
Calculate how many basil plants you want to grow. With regular harvesting and pruning, each plant can produce 15 to 25 cups of basil. Since you can harvest and dry basil for off-season use, plan to grow enough to last you an entire year. Keep in mind that basil plants grown for harvesting are planted 12 to 15 inches apart. On the other hand, basil plants grown for ornamental purposes need at least 24 inches to grow to their mature size; however, each specific variety has different spacing needs.
Purchase small-established basil plants from a local or online nursery, at a farmer's market or through a nursery catalog. Buy them in the early spring after the last frost in the spring. Choose plants that have strong stems with leaves that are crisp and are free from insect damage and brown spots.