Varieties of Oranges

The initial introduction of oranges (Citrus sinensis) to North America is hard to trace. Christopher Columbus reportedly planted oranges on Hispaniola around 1493. In 1513, Ponce de Leon and his sailors planted Florida's first orange trees. Oranges grow in tropical and subtropical regions, favoring temperatures ranging from 55 to 64 degrees Fahrenheit in winter and up to 95 degrees F in summer. Oranges are the sweetest when grown in areas with warm days and cool nights to facilitate sugar formation.

Sweet oranges are just that -- sweet. This group includes round orange varieties such as navel oranges, Valencias, and blood oranges. Navel oranges, those with a little button on the end away from the stem, are considered the finest oranges for simply peeling and eating. Their skin often falls away in one or two segments, revealing the juicy sections. The Cara Cara orange, a type of navel orange, is considered a specialty orange, available in the winter months, and has pink inner flesh. Valencias, while sweet, do have a few seeds and are used most often for orange juice. The vividly red interiors of blood or moros oranges get red color from high concentrations of anthocyanin, a powerful antioxidant. All members of the species Citrus sinensis, of which sweet and bitter oranges are members, thrive in U.S. Department of Agriculture plant hardiness zones 9 through 11.

Like sweet oranges, bitter oranges are true to their name. These citrus trees originated in Asia and it is thought that Spaniards introduced these oranges into Florida. Some varieties of these oranges are grown commercially for their fruit, but more often sweet orange varieties are grafted onto the hardier bitter or sour orange root stock. Wild stands of sour oranges can still be found growing in the Everglades on hammocks of land where native dwellings once stood.

Mandarin oranges (Citrus reticulata) are the cuties of the orange world. They are small, sweet and easily shed their thin, loose skin when peeled. Marketed under such fanciful names as Cuties or Clementines, they are a favorite fruit in stores at Christmas. Considered a sweet orange by most, mandarins are now classified under their own species name. Mandarins are more cold hardy and drought tolerant than sweet oranges and are grown primarily in Alabama, Florida and Mississippi. Mandarin oranges are hardy in USDA zones 8b to 11.

Oranges are grown best in subtropical areas, although they are found throughout the world in tropical climates. Most sweet oranges, nursery plants or commercial trees are actually grown on sour orange root stock. Warm, humid conditions will produce thin-skinned, sweet fruit with light orange peel and light yellow inner flesh. Trees grown in cooler climates, such as California or Arizona, will produce fruit with dark orange peel and brightly colored flesh. Plant oranges in a full-sun area on the south side of gardens or houses. They do best in moist, well-drained loamy soil that is acidic. Plants installed near houses or buildings should be planted at least 12 feet away to allow for mature spread.