Where Do Pistachios Grow in the U.S.?

Temperature

• For pistachio trees to produce nuts, temperatures have to be right. Pistachios thrive on long hot summers. Temperatures over 100 degrees Fahrenheit produce larger and more abundant nuts. Pistachios also need a dormancy period triggered by winter cold. Temperatures must be less than 45 degrees F to ensure dormancy. However, pistachios will tolerate temperatures as cold as 27 F only for short periods of time. Ten degrees F can kill a pistachio tree.

Growing Area

• Strict temperature requirements limit where pistachios will grow. However they can do well in many areas that do not produce nuts commercially. Parts of the states farthest south in the U. S. and some areas in Washington and Oregon have the right conditions as well as most of California. Some areas of Hawaii have cool enough winter temperatures to grow pistachios as well.

Water

• Pistachios are drought-resistant, although nut production will drop during drought conditions. To produce nuts the tree must have adequate water -- moistening soil to 4 feet deep -- in late winter, spring and early summer. Pistachios will not tolerate wet roots, however, so should not be planted close to areas where water ponds or that have rivers. Spring moisture is important, as that is when pistachio trees put out new growth. This includes creating flower buds for the next year’s harvest as the nuts have a two-year maturation cycle. Water requirements may make producing pistachio nuts difficult in areas where temperatures are right but there is too much or too little water.

In the Garden

• While temperature and water needs may seem restrictive pistachios have advantages for gardeners in the areas they will grow. Pistachio trees have few pests, so they need little spraying or other forms of pest management. They also grow in a variety of soils so there is little need to amend soil when planting. Pistachios grow slowly so, although it will take five to six years to produce their first crop, they are not likely to outgrow their location. Mature trees will reach 20 to 30 feet tall. Two trees are needed, a male and female, as they are wind-pollinated rather than relying on insects such as bees.