The pistachio, a member of the cashew family, is a small tree originating from Central Asia and the Middle East. The tree produces seeds that are widely consumed as food.
Pistacia vera is often confused with other species in the genus Pistacia that are also known as pistachio. These other species can be distinguished by their geographic distributions (in the wild) and their seeds which are much smaller and have a soft shell.
- Botanical Name: Pistacia vera
- Common Name: Pistachio tree
- Plant Type: Fruit
- Mature Size: 25 to 30 feet tall
- Sun Exposure: Full sun
- Soil Type: Light, well-draining, sandy, loamy
- Soil pH: Neutral to slightly alkaline
- Bloom Time: Spring
- Flower Color: Reddish-brown buds
- Hardiness Zones: 7 to 11
- Native Area: Central Asia
- Toxicity: Toxic to horses
The tree grows up to 10 m (33 ft) tall. It has deciduous pinnate leaves 10–20 centimeters (4–8 inches) long. The plants are dioecious, with separate male and female trees. The flowers are apetalous and unisexual and borne in panicles.
The fruit is a drupe, containing an elongated seed, which is the edible portion. The seed, commonly thought of as a nut, is a culinary nut, not a botanical nut. The fruit has a hard, cream-colored exterior shell. The seed has a mauve-colored skin and light green flesh, with a distinctive flavor. When the fruit ripens, the shell changes from green to an autumnal yellow/red and abruptly splits partly open. This is known as dehiscence, and happens with an audible pop. The splitting open is a trait that has been selected by humans. Commercial cultivars vary in how consistently they split open.
Each pistachio tree averages around 50 kilograms (110 lb) of seeds, or around 50,000, every two years.
How to Plant Pistachio Trees
Pistacia vera is a dioecious variety of fruit tree. In simple terms, this means that they are not self-pollinating. A tree will either have male or female flowers, and you’ll need one of each if you want to actually produce pistachio nuts.
Gusty winds in the spring and summer are crucial for a healthy pistachio harvest. The pollen from the male trees must have enough wind to blow from the male flowers to the female tree’s flowers. Typically, trees planted within 50 feet of each other will be able to pollinate.
Pistachio Tree Care
Growing pistachios isn’t an option for everyone because of their specific climate needs. The biggest factor to consider is the temperature, humidity, and rainfall of your area. Pistachio trees require very hot temperatures during the day and don’t appreciate high humidity or wet soil. It does best in sandy, well-draining, loamy soil. Infrequent, deep waterings are best.