Climates for growing Citrus Trees

[Dave]

Citrus trees are not generally frost hardy. A few hardy hybrids can withstand temperatures somewhat below freezing, but do not produce quality fruit. In the U.S., Florida, Texas, and California are major commercial citrus-producing regions, while smaller plantings are present in other Sun Belt states.

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 blossom 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.

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 and tangors can be grown outside even in regions with sub-zero winters, although this may affect fruit quality.