BASIL
Ocimum basilicum: Grows to 3 feet tall. Full sun. Regular water.
Produces masses of aromatic leaves all summer. Snip off flower stalks as soon as they appear to prevent the plant from going to seed. There are dozens of varieties of basil available: purple basil, lemon basil, licorice basil, Thai basil and more. Basil is easy to grow from seed. Low temperatures and cool soil are enemies of basil seedlings, since the combination leads to damping off, and basil is very susceptible. Plant when the soil is warm, or use heating mats if starting seed indoors.
PARSLEY
Petroselinum crispum: Grows to 12 inches tall. Full sun. Regular water.
Parsley produces leaves its first year. In its second year, it produces yellow flowers and seed, then dies. It's famous for being finicky to start from seed, so buy starts from the nursery. It comes in curled or flat-leaf varieties. Both have the same fragrance.
SAGE
Salvia officinalis: Grows to 2 feet tall and as wide. Sun. Limited water.
Sage's woolly gray leaves are gorgeous. And they come in purple, green and gold as well as tricolor (purple, white and green). The plain green one is the typical culinary sage and the hardiest. It sends up spires of blue flowers in summer that are beautiful in arrangements.
THYME
Thymus vulgaris: 6 to 10 inches tall; can spread wider. Sun. Limited water.
Thyme is a versatile plant. It can be a ground cover that creeps and crawls along the ground, smothering weeds. It's the perfect herb for soups, stews and poultry. It also looks good among roses. Some gardeners use it as a lawn substitute or let it grow among the grasses in a traditional lawn. It comes in many flavors, including lemon and lime. In fact, there are hundreds of varieties of thyme. It, too, can get woody, but responds well to being sheared to the ground.