The origins of bergamot orange (Citrus bergamia, also known as Citrus aurantium subspecies bergamia) are shrouded in mystery. This small orange tree grows almost exclusively in Calabria, Italy, where it was introduced in the 1700s. Like sour orange (Citrus aurantium), bergamot orange can grow in U.S. Department of Agriculture plant hardiness zones 9 through 11, but it is sensitive to adverse growing conditions. Its rind yields bergamot essential oil.
Bergamot is probably a hybrid between sour orange and some kind of acid lime, perhaps the Mediterranean limetta (Citrus limetta), which also have a similar oil and are sometimes incorrectly called bergamot. Thought to be a seedling discovered in southern Italy, bergamot's original use was as the primary ingredient in cologne water, or eau de cologne, invented in 1676 by an Italian emigrant to Cologne, Germany. Still used in perfumes, bergamot oil is in 34 percent of today's women's perfumes and 50 percent of men's fragrances. The oil is also used to flavor Earl Grey tea, wine and tobacco.
Approximately 7,500 acres in the southern seacoast area of Calabria, Italy, are devoted to bergamot orange orchards. This area gives the best and most consistent bergamot oil quality. Plantations in other parts of the world yield fruit, but the University of California, Riverside, notes that the essential oil quality is variable and inferior to that from Calabrian oranges. Small plantations exist in Sicily, North Africa, Turkey, the Ivory Coast and New Guinea. Bergamot is sensitive to wind and extremes of drought and moisture. Coastal Calabria has mild winters, the highest number of sunshine hours in Italy, no frost and small differences between day and night temperatures, with an average annual rainfall of 22 inches, mostly in the winter.
Medium-sized trees can grow to 40 feet tall but are usually kept pruned to around 15 feet high in cultivation. Fragrant white flowers produce a rounded, often pear-shaped yellow fruit with a highly fragrant thin rind, sour juice and sour pulp. The name "bergamot" is thought to come from the Turkish "beg-armudi," which means "prince's pear." Flowers appear in March through April, with fruits ready to pick in December through February. Fruit quality is dependent on essential oils formed in the rind. Mild, Mediterranean-type regions such as Calabria are ideal growing zones because essential oil production is particularly affected by temperatures during the first phases of fruit development and again in mid-summer.
Bergamot has three cultivars: "Castagnaro," "Femminello" and "Inserto," also known as "Fantastico." "Inserto" is a hybrid between "Castagnaro" and "Femminello" and is a widely grown cultivar. It has vigorous growth and yields well. The trees need weed-free growing conditions and supplemental irrigation. Orchards in zones with climates similar to Italy's dry-summer regions need an additional 10 inches of water per acre applied yearly. A tree that is occasionally sold as bergamot in the United States is "Bouquet des Fleurs" (Citrus aurantium "Bouquet des Fleurs"), a variety of sour orange, which is a semi-dwarf variety with very sour fruit grown for marmalade. It has a high essential oil content and one of the strongest fragrances of any citrus flower.
- World Agroforestry Centre: Agroforestry Tree Database: Citrus Bergamia
- University of California Riverside Citrus Variety Collection: Bergamot Sour Orange Hybrid
- New Perfume Handbook; N. Groom
- Purdue University NewCrop Program: Fruits of Warm Climates: Sour Orange
- University of California Santa Cruz: Center for Agroecology & Sustainable Food Systems: Citrus Offers Year-Round Options
- Arizona State University: Citrus Aurantium