The origins of the pistachio nut can be traced back to the Middle East and central Asian countries.
Archeologists have found evidence in a dig site at Jarmo, near northeastern Iraq, that pistachio nuts were a common food as early as 6750 BCE. After that the pistachio nut was not accounted for in history until about 2000 BCE when the Near East sprouted in population and less common foods such as pistachios were rediscovered and even cultivated. The hanging gardens of Babylon were said to have contained pistachio trees during the reign of King Merodach-baladan about 700 BCE.
The nut is even mentioned in the Old Testament in the bible. "So their father, Jacob, finally said to them, 'If it must be, then do this: put some of the best products of the land in your bags and take them down to the man as gifts--a little balm, a little honey, some spices and myrrh, some pistachio nuts and almonds.'" (Genesis 43:11)
In the first century AD the pistachio made its debut in Rome via the Emperor Vitellius. Apicius. The nuts traveled from Syria to Italy in the first century AD and spread throughout the Mediterranean from there.
The Persians used the pistachio nut as an important ingredient for sweets as well as in other foods. When the Arabs settled in the southern part of Spain, known as Andalusia, and in Sicily during medieval times, they introduced many foods from their native lands such as the pistachio nut. California encountered the pistachio in 1854 when Charles Mason, a seed distributor for experimental plantings, brought the pistachio to this country. Several years later, in 1875, a few small pistachio trees planted in Sonoma, California.
Today, California is the second largest producer of pistachio nuts after Iran.
Pistachio trees grow in poor soil where other trees will not survive, what is important to their survival is the proper climate. Pistachio trees flourish in hot dry summer weather and prefer cool winters, and would not survive in humid or damp areas. The pistachio tree takes five to eight years to begin bearing some fruit and it is not until the 15th and 20th year that they reach maturity and bear fully. Alternate years produce a heavy crop. The trees develop a brownish green flower in spring and ripen in late summer or early autumn. The pistachios then split open along their seams.
Harvesting pistachios takes place in the late summer or early autumn when the hulls that cover the shell become loosened from the nut and obtain a redish color. The outer hulls are then quickly removed in order to preserve the white appearance of the shells and prevent staining.