Walnut Day
Walnut Day is held on May 17. This event in the second decade of the month May is annual.
99% of the commercial U.S. supply and 3/4 of the world trade of walnuts now come from California. Walnuts are the oldest known tree food — they date back to 10,000 BC! English walnuts (also known as Persian walnuts) originate in Central Asia and were introduced to California in the 1700s. California is home to nearly 325,000 acres of walnut orchards.
Walnut trees take about 5 years before they are considered productive, after which they produce an annual crop for 30 to 40 years. It takes about 170 days for a walnut to develop and mature on a tree.