Winter Fruiting Citrus Trees

Photo Courtesy of Andy Jien

In a previous blog post, we talked about two of the few fall fruiting trees, Persimmons and Pomegranates. Today's blog will be about citrus trees, some of the few winter fruiting trees. Citrus is a commonly used term that refers to several of the flowering varieties of the genus Citrus; the fruiting trees included within this genus are: lemons, limes, oranges, grapefruit, tangerines, and most species of kumquats.

Some of the earliest species of citrus trees are believed to originate from Southeast Asia near the area bordered by Myanmar (Burma), Northeast India, and the southwest corner of China (Yunnan province). Citrus trees were brought over to Europe from Asia and many of the citrus trees we see in California are decendents of the ones grown in the mediteranean regions of Europe. Citrus trees were commonly grown throughout Southern California around the turn of the century and well into the middle of the twentieth century; in fact, citrus fruit production is what attracted many of the first settlers to the Inland Empire and Orange County (appropriately named after the orange). Throughout human history, citrus have been cultivated and revered not only for their culinary properties, but their health benefits as well.

Citrus trees come in many different sizes and colors. There are standard varieties which grow to be approximately15-25 ft. in height, semi-dwarves are roughly between 8-15 ft. tall, and dwarves (which are the variety at most of the IEUA's school gardens) are about 4-8 ft. tall. Citrus trees begin to flower in the fall and by December most of their fruit have developed. They need a diurnal winter to change color, so our Mediterrenean climate is perfect for witnessing some of the beautiful colors of some citrus species. Some citrus trees grown in tropical locations never experience cool temperatures, which makes them stay green year round even when ripe.

If you live in an area that is near the Inland Empire Utilities Agency (Chino, Montclair, Ontario, Upland, Rancho Cucamonga), then it is likely that citrus trees have played a role in your city's history. As a fun project, have your students research the role that citrus played in your city. Try to find out which species of citrus were grown in your area and by whom.

For more reading on citrus and its role in Inland Empire history, please see the following websites:

http://en.wikipedia.org/wiki/Citrus                   Time line of Citrus in the Inland Empire: