The Citrange

January 8, 1892
Today is the birthday of the agricultural botanist and plant wizard Walter Tennyson Swingle.

Walter was a very popular botanist during his lifetime. Walter introduced the Date Palm to California, and he created many new citruses through hybridizing.
In 1897, Walter made the first man-made cross of a Bowen Grapefruit and a Dancy Tangerine in Eustis, Florida.

In 1909, Walter created the Limequat, a cross between the Key Lime and the Kumquat. That same year, Walter created the Citrangequat, a trigeneric citrus hybrid of a Citrange and a Kumquat.

Walter developed the Citrange, a combination of the Sweet Orange and the trifoliate orange, as he was attempting to breed an orange tree that could withstand colder weather.

Walter was born in Pennsylvania. He knew all about cold weather. His family quickly moved to Kansas, where Walter was home-schooled and ultimately educated at Kansas State Agricultural College.  In short order, Walter began working for the government at the United States Bureau of Plant Industry in the Department of Agriculture. And the USDA immediately put him to work, sending him to nearly every country in the world.
Walter brought Egyptian Cotton to Arizona and Acala Cotton to California.
However, Walter's most significant accomplishment was the introduction of the Date Palm to America. The Date Palm was something swingle discovered during a visit to Algeria. And this is how we know how clever Walter was - he was indeed intelligent and observant because he noticed that Algeria’s climate and soil mirrored that of California.
In fact, Walter was optimistic about the Date Palm's chances in California right from the get-go, writing:

“No heat is too great and no air too dry for this remarkable plant, which is actually favored by a rainless climate and by hot desert winds. 
The Date Palm can withstand great alkali quantities in the soil- more than any other useful plant… 
It is probably the only profitable crop that can succeed permanently."

Now when the Date Palm arrived in California, the Coachella Valley was identified as the perfect spot to grow them. By 1920, over a hundred thousand pounds of Dates were grown in California.
Thanks to Walter Swingle, Dates are one of California's main exports. Today, the total value of the Date crop is approaching $100 million every single year.


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Walter Tennyson Swingle
Walter Tennyson Swingle

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