SONOMA, Calif. - The olive tree was first introduced to California by Spanish priests of the Franciscan, Dominican, and Jesuit orders who founded missions in the New World. By the mid-18th century, there were 20 missions dotting Baja California, most with orchards and gardens that featured the Mediterranean trees most familiar to their inhabitants: olives, pears, pomegranates, and figs.
As the padres headed north to establish missions in Alta California - what we know today as the state of California - they continued to plant olive groves. They pressed olives into oil for cooking and lamplight, and for medicinal, machinery, and ceremonial use. The Mission olive varietal is unique to these missions and is now considered a fruit of the Americas, since it is no longer found in Europe.