Given well-prepared soil and full sun, herbs are quite easy to grow. Compared to some other garden plants, herbs are not often attacked by insects or diseases. Small quantities of culinary and medicinal herbs sell for relatively high prices, so herbs in general are a profitable crop. By growing and marketing certain herbs at the right time of year, some can be more profitable than others.
Basil offers a good return early in the season, and reaches its marketing peak when tomatoes start appearing. Later in the summer, cooks buy large quantities of basil to make pesto sauce. Basil is easy to grow from seed, but the early crop must be started indoors or in a greenhouse so it is ready for harvest in the spring.
A staple ingredient in Asian and Latin American cuisines, cilantro is increasingly popular in western dishes as well. It grows easily and reliably from seed, but it must be planted often---every two weeks or so---because most varieties bolt (go to seed) quickly and become unmarketable.
This is a perennial, and plants that are well cared for will produce for many years. The fragrant flowers are used in perfumes, skin care products, pot-pourris and sachets. The flower stems are cut and bundled when the flowers are just beginning to open, and fetch high prices. Some varieties are more fragrant than others---among the best are 'Hidcote' and 'Munstead.'
A perennial, rosemary fetches high prices at market. Varieties such as 'Arp' and 'Gorizia' put up long spears that are popular with chefs and home barbecue fans. Rosemary is also used in skin-care products. The plants need winter protection in cold climates, and much commercial production is in greenhouses and plastic-covered hoophouses.
There are two kinds of parsley: flat leaf and curly leaf. Most chefs use the flat leaf kind, which is flavorful and easy to clean. The curly leaf varieties are equally flavorful, but are used mostly as a plate garnish or display decoration---fresh fish displays are often surrounded by parsley. It can be profitable if sufficient quantities are grown, since individual bunches sell relatively cheaply, but it is easy to grow and harvest.