The pistachio (pistacia vera), a high desert tree, originated in western Asia (Iran) and Asia Minor, made its way into Mediterranean Europe .
To grow and bear fruit they require very hot summers (more than 600 hours >30C); very cold winters (more than 1,000 hours Summer and autumn rains may induce fungal problems and harvest difficulties.
Pistachio trees grow best and produce the most nuts in an arid semi-desert climate with long, dry, hot summers, low humidity and cool but not frigid winters. During the growing season, pistachio trees thrive on heat. Summer temperatures of around 37 degrees Celcius produce large quantities of the best nuts. In pistachio, male and female flowers are produced on seperate trees. A female tree planted singly will not produce nuts unless a male tree is growing nearby. For the best chance of pollination, plant a male upwind of every 10 to 15 male trees.
Pistachio orchards are planted in areas with frequent but mild spring winds to pollinate the blossoms. After shedding their leaves in the fall, pistachio trees need a winter dormancy period of about 6 weeks with temperatures below 7.2 degrees Celcius.
A good summary of growing pistachios under Australian conditions is in the book: “A Handbook for Farmers and Investors”, published by the Rural Industries Development Corporation: Pistachios
Some cities producing pistachios in Iran : Rafsanjan, Sirjan, Damghan & …