Citrus: Encyclopedia II - Citrus - Culture

Citrus - Culture

Citrus trees are not generally frost hardy. Citrus reticulata tends to be the hardiest of the common Citrus species and can withstand short periods down to as cold as −10 °C, but realistically temperatures not falling below −2 °C are required for successful cultivation [1]. A few hardy hybrids can withstand temperatures well below freezing, but do not produce quality fruit. A related plant, the Trifoliate orange (Poncirus trifoliata) can survive below −20 °C [2] but the fruits produces are extremely astringent and inedible.

The trees do best in a consistently sunny, humid environment with fertile soil and adequate rainfall or irrigation. Though broadleaves, they are evergreen and do not drop leaves except when stressed. The trees flower in the spring, and fruit is set shortly afterward. Fruit begins to ripen in fall or early winter months, depending on variety, and develops increasing sweetness afterward. Some varieties of tangerines ripen by winter. Varieties such as the grapefruit may take up to eighteen months to ripen.

Major commercial citrus growing areas include southern China, the Mediterranean region, South Africa, Australia, the southernmost United States, and parts of South America. In the U.S., Florida, Texas, and California are major producers, while smaller plantings are present in other Sun Belt states.

Citrus trees grown in tubs and wintered under cover were a feature of Renaissance gardens, once glass-making technology enabled sufficient expanses of clear glass to be produced. The Orangerie at the Palace of the Louvre, 1617, inspired imitations that were not eclipsed until the development of the modern greenhouse in the 1840s. An orangery was a feature of royal and aristocratic residences through the 17th and 18th centuries. In the United States the earliest surviving orangery is at the Tayloe House, Mount Airy, Virginia.

Some modern hobbyists still grow dwarf citrus in containers or greenhouses in areas where it is too cold to grow it outdoors. Consistent climate, sufficient sunlight, and proper watering are crucial if the trees are to thrive and produce fruit. For cooler areas, lime and lemon should not be grown, since they are more sensitive to cold than other citrus fruits. Tangerines, tangors and yuzu can be grown outside even in regions with sub-zero winters, although this may affect fruit quality.

Adapted from the Wikipedia article "Culture", under the G.N U Free Docmentation License. Please also see http://en.wikipedia.org/wiki