Florida orange juice drinkers may recognize the “sweet orange” Citrus Sinensis variety, the most commonly cultivated orange tree in the United States, by their fruits, the Hamlin or the Valencia. The cold-tolerant Hamlin, harvested between October and January, and the double fruit-bearing Valencia, harvested from March to June, comprise the bulk of Florida’s commercial orange tree crop. But there are also other popular Citrus Sinensis cultivars, including blood oranges, a smaller fruit with crimson flesh, and navel oranges, also grown in California. The Citrus Sinensis tree can reach a height of 20 to 30 feet with a rounded crown of leathery, shiny leaves that can spread up to 20 feet wide. They need full sun to produce the most fruit. They can be drought tolerant, with some fruit damage the more severe it is, and may need protection if the temperatures fall below 24 degrees Fahrenheit.
A smaller, spiny tree reaching between 15 and 20 feet, the Citrus Reticulata also produces sweet, juicy fruit; but unlike the Sinensis, the flesh of Reticulata oranges comes in easily separable sections. Better known as mandarin or tangerine oranges, Citrus Reticulata fruit can be juiced just as well as Sinensis cultivars. While tangerine orange juice is commercially marketed, most Reticulata cultivars are eaten by hand. This variety of sweet orange matures early in the harvesting season, beginning in either November or December. Citrus Reticulata trees need full sun to bear the most fruit. The trees can easily survive a drought but will not produce much fruit. While sudden freezes below 25 degrees Fahreheit can be damaging, some Reticulata trees can acclimate to lower temperatures if they come gradually.
Most of the fruits from spiny Citrus Aurantium trees with compact crowns that can range from 10 to 30 feet in height live up to their common sour orange name. Citrus Aurantium cultivars like the Mediterranean Seville or the Italian Bergamot are used to make marmalade or tea. Others make oils and perfumes. The Italian chinotto tree, a myrtle-leaved Aurantium cultivar, makes a bitter orange soft drink of the same name as well as the Campari apertif. Despite its sour name, some seedy Aurantium fruit produce bittersweet juice for different cultural tastes, including the Paraguay from South America and two Chinese cultivars, the Vermillion Globe and the Leather-Head. Unlike the Sinensis or Reticulata varieties, Citrus Aurantium oranges are oblate or oblong-oval shaped. Citrus Aurantium trees are among the hardiest citrus trees. They can thrive in imperfect soil and with little cultivation. They start to bear fruit early in the season, beginning in October.