The small, crunchy pistachio nut is something you can easily grow in your backyard if you live where the summers are long and hot and winters are moderately cold. It needs 600 hours of cold to cause flower buds to open. This tree cannot tolerate high humidity and rainfall, so it is not suited to growing in tropical regions. Native to Iran and the former Soviet Union east of the Caspian Sea, the pistachio grows slowly to about 30 feet tall and has a very deep root system, making it drought tolerant. Pistachios don’t perform well as potted plants.
Plant at least two pistachio nut trees—one male and one female—because female trees require male pollen in order to produce nuts.
Dig a planting hole in an area with full sun that is slightly larger than the tree’s root system. Mix any type of organic compost with the soil you dig out, using about one part compost to four parts soil.
Cut the bottom out of the tree’s nursery pot and cut off any long roots curled up at the base. Then cut up one side of the pot, but leave the tree in it. Place the tree in your hole and fill with loose soil/compost. Pull the pot off gently and firm the soil around the trunk. Water well by running a hose at a slow drip for one hour or longer.
Water your pistachio tree to keep the soil moist but not soggy from April through September. Avoid watering in October and November—this helps the tree to enter its dormant period. During winter, water your tree once each month, which will help it to withstand cold temperatures.
Fertilize once each spring with a plant food designed for trees that has an equal balance of nitrogen, phosphorus and potassium, such as one having an N-P-K ratio of 10-10-10.
Prune your young pistachio tree to a central leader limb with four or five scaffold limbs at least 4 feet above the ground level.