Last Updated Dec 11, 2012 · Written by Craig Gibson
Pistachio trees are native to Western Asia and Asia Minor. Evidence has shown that they have been used as a food since as early as 7,000 BC. These nuts are great for eating, and if you live in the right area, you can grow them yourself. Read on to learn more.
Pistachios grow best in areas that have long, hot, dry summers and cold winters. The trees are slow growing and will stand at about 30 feet or 10 metres high when fully grown. They prefer well drained soil and cannot tolerate excessive dampness or areas that have high humidity. They are drought resistant. Pistachios are deciduous and are dormant throughout the winter months.
To plant a pistachio tree, simply dig a hole that is slightly bigger than the pot. The soil in the point should be the same level as the ground once it is planted. Remove the pot, and see if there are any roots curled around the bottom. If there are, cut these off even with the soil. This may seem counterproductive but it will actually encourage more roots to form. Once the tree has been placed, backfill the hole and firm the soil down to remove air pockets. Water the tree in well. Do not fertilise during the planting process, however, you can fertilise with a good tree fertiliser that contains nitrogen, phosphorus, and potassium each spring.
When watering the tree, ensure that it has a good amount of water throughout the warmer months (September – March). Don’t water the tree from April to May as this will help the tree to go dormant for winter. Once dormant, watering the tree monthly will help it to become more cold resistant.
Pistachio trees will take 5 to 8 years to start bearing nuts but it will take 15 to 20 years to achieve their full capacity. In Australia, you can harvest the pistachios in February. If the summer is much hotter than usual, you may be able to harvest early. To tell if the nuts are ripe, simply squeeze the nut between your thumb and forefinger. If the hull comes apart and can be peeled off, the nut is ripe. The hull of the nut will also change colour – when it is ripe, it will be a light yellow colour. The pistachios will fall off the tree when it is shaken in some way. Place some form of tarp or cloth underneath the tree to catch the nuts.
Remove the hull of the nut within 24 hours of harvesting. If it is left on, it will stain the inner shell. This can be done by hand. Once removed, rinse the nuts in cold, clean water and allow them to dry.