The scientific name for the pistachio is Pistacia vera L. It is a member of the family Anacardiaceae which contains such widely known plants as the cashew, mango and poison oak.
It is a deciduous tree, requiring approximately 1,000 hours of temperature at or below 45° F. in order to grow normally after its winter dormancy. Pistachio nut trees, generally, are suited for areas where summers are long, hot and dry, and the winters are moderately cold. A native desert tree, it does not tolerate high humidity in the growing season.
The trees are dormant from December through February and begin to bloom with the arrival of warmer weather in late March. The male pollinates the female via the April winds, and the shell of the nut is fully developed by mid-May. Before June ends, the seed inside the shell has begun its rapid expansion and by the first of August, the seed has filled the shell. The nuts, splitting at the seams, are usually ready to be harvested the first week of September.
Pistacia vera L. probably originated in Central Asia where large stands of wild trees are found in areas known today as Iran, Turkey and Afghanistan. The first commercial plantings in these countries were most likely started from seeds collected from the best wild trees. The tree was introduced into Mediterranean Europe at about the beginning of the Christian era. The climate in the Tularosa Basin is almost identical to the pistachio producing areas of Iran and Turkey. The altitude of both areas is identical.
Although the pistachio was first introduced into California by the US Department of Agriculture about 1904, very little interest was generated until the 1950’s. Since that time, pistachios have become a significant farm commodity in California.
Plantings have also been made in Arizona, New Mexico and Texas in those areas that meet the climate criteria. The tree flourishes and bears well in well-drained soils, but its root system will not tolerate prolonged wet conditions. It seems more tolerant to alkaline and saline conditions than most other commercial trees. The vigor and productive life of the tree is extremely long lasting. In the mid-East, there are trees on record of having productivity of several hundred years.
The pistachio is a small tree, reaching about 30 feet of height at full maturity. Usual commercial plantings are approximately 120 trees per acre. They begin to produce nuts in the 4th or 5th year after planting, and good production takes 8 to 10 years, with full bearing maturity occurring after 15 to 20 years. Average yield per tree is 1/2 lb the 5th year, increasing to up to 20 lb at maturity.
A large percentage of pistachios is marketed in the shell for eating-out-of-the-hand snack food. Pistachios are a rich source of essential nutrients, fiber and protein. Low in saturated fat and cholesterol free, increasing numbers of people are discovering how enjoyable this delicious nut can be.