Leading areas of rosemary production are the Mediterranean countries, the United States, and England. The drought tolerant plant grows in rocky to sandy soils, as long as there is adequate drainage and a minimum soil depth of about 0.2 meters. The pale-blue flowers can develop throughout the growing season, although profuse blooming occurs during late winter or early spring. Rosemary has no serious pests or diseases. The plant is not cold hardy.
Commercial production is from both cultivated and wild plants.
Fields of rosemary are usually harvested once or twice each year, depending upon the geographical area and whether the harvest is for plant material or essential oil. A first cutting can be obtained in the seeding year but is usually delayed until 18 months after seeding. Leaves are dried in the shade directly after harvest to maximize retention of color and aroma. There is some loss of color when leaves are frozen. The oil is extracted from flowering tops, stems, and leaves by steam distillation or the use of organic solvents.