Plant Palette

Plant Palette


Photo of Jennifer Schultz Nelson

Jennifer Schultz Nelson
Extension Educator, Horticulture

Winter is the season for citrus. One of my favorites is the Clementine. But what exactly is a Clementine? This question has sparked a lot of debate in our office.

I always thought Clementines were the same as mandarin oranges. Not quite. Any inquiry into the heritage of citrus fruits turns up a family tree originating in South- and Indo-China that is quite complicated. Clementines are part of a group known as mandarins, but they are not the same canned fruits so often used in salads and desserts. Most canned mandarins are technically Satsumas, originally from Japan. Another term for mandarins is tangerines.

A French missionary in Algiers named Father Clement Rodier developed the Clementine in 1902 from a cross between a tangerine and the Seville, or bitter, orange. The resulting fruit became very popular because not only were they very easy to peel, and delectably sweet, they were also seedless. Their popularity continues to increase today. U.S. consumption of Clementines has risen from 33 million pounds in 1994/95 to 119 million pounds in 2002/03.

Historically, Spain and Morocco have been the major producers of Clementines, because they have the hot and arid environment Clementine trees require. Management of Clementine orchards is quite intense–most of the work is still done by hand. Both countries have laws designed to maintain high quality in their Clementine harvests.

The laws revolve around placement of viable pollen sources for Clementines. Clementines have no seeds because they cannot self-pollinate, and many other Clementine and citrus pollens cannot pollinate their flowers either. However there are many citrus pollens that will pollinate and produce seed in Clementine fruit, and these laws limit where or if they can be planted where Clementines are grown.

This cross-pollination issue is one factor limiting Clementine production in the U.S., specifically California. Though citrus is also grown in the hot climate of Texas and Florida, both are far too humid for Clementine production. California has a great climate, but there are far too many other citrus varieties grown there that contaminate the Clementines and result in a very seedy, low-quality fruit. Researchers are investigating ways to avoid this problem so that the U.S. can produce more of this highly desirable citrus fruit.

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