Facts for Kids

A pistachio is the seed of a small to medium tree that people eat as a snack. The tree’s scientific name is Pistacia vera, and it belongs to the same plant family as the cashew. People usually call the seed a “nut” because we eat it like a nut, but botanists place it in a different group of fruits. Pistachios are popular all over the world because they are tasty, crunchy, and can be used in cooking and sweets.

Pistachios are desert-loving plants that do well in hot, dry places. They can handle salty soil better than many other trees and need a sunny spot with soil that drains well so the roots do not stay wet. They do not like high humidity and can get sick if the ground stays soggy.

These trees need long, hot summers so the seeds ripen properly. They can survive a wide range of temperatures, from about −10 °C (14 °F) up to 48 °C (118 °F). Pistachios come from the dry regions of Iran and Central Asia.

Pistachio kernels are eaten in lots of tasty ways. People enjoy them fresh from the shell or roasted and salted as a snack. They are also used in sweets and dishes: try pistachio ice cream, baklava, pistachio butter or paste, Indian sweets like kulfi, and treats such as biscotti or spumoni.

Long ago, shells were dyed red or green by hand so they looked nicer in markets. Now most are harvested by machines and left their natural pale color. Pistachios appear in foods from many countries, especially Persian and Indian cooking, where their flavor and color are prized.

The name pistachio is like a word that traveled across countries. Long ago people in the area we now call Iran used a word like "pistakē" for the nut. That word moved into Greek as "pistákion," and then into Latin. From Latin and Greek it went into Old French, where English first heard a similar form in the Middle Ages.

Later, in the 1500s, the Italian word "pistacchio" became popular and helped shape the name we use today. Because the nut was traded and carried by people, many languages kept similar-sounding names. It's a little like a nickname that changes as it goes on a journey.

People have eaten pistachios for thousands of years. Archaeologists found pistachio remains at sites in Central Asia that date back to around 6750 BCE, showing people collected and ate them long ago. Ancient stories and writers mention pistachios in places like Syria and the lands east of the Mediterranean.

The Romans brought pistachio trees into parts of Europe in the 1st century AD, and people later grew them across southern Europe and North Africa. Over many centuries, farmers and gardeners spread the trees along trade routes and learned how to grow them in new lands.

People began growing pistachios for sale in places like the United States and Australia in the 1800s and early 1900s. Plant explorers brought stronger types of pistachio to California in the early 1900s, but it took a few decades before large orchards appeared. One important step came in the 1970s when tax rules and new plant types made pistachio farming more attractive, and California had its first big commercial harvest in 1976.

Around the world, Iran long grew many pistachios, and by the 2000s the United States and Iran were the largest exporters. Today most of the world’s trade comes from these two countries, with many small farms in Iran and hundreds of larger producers in the U.S.

Pistachio trees can grow up to about 10 metres tall (around 33 feet) and lose their leaves each year. Their leaves are made of many small leaflets and are about 10–20 cm long (4–8 inches). Trees are usually either male or female, so farmers plant both kinds so the female trees can make seeds.

The fruit is a drupe, a type of fruit that holds one long seed inside. The shell is hard and cream-colored and the seed has a thin mauve skin over bright green flesh with a special, nutty taste. When ripe, many shells split open with a little pop — people bred trees so the shells open easily. A mature tree can make around 50 kilograms (110 pounds) of seeds every two years.

Pistachios are a source of energy, healthy fats, protein, and some vitamins and minerals. The FDA allowed a health claim in 2003 that eating about 1.5 ounces (a small handful, about 42.5 grams) of nuts each day, as part of a diet low in saturated fat and cholesterol, can help lower the chance of heart disease.

Research also shows pistachios may help lower blood pressure for some people and can reduce a type of blood fat called triglycerides when eaten regularly for a few months. When eaten in normal portions, pistachios are not usually linked to weight gain and can be part of a healthy diet.

Pistachio trees can get sick from fungi and bothered by insects, and the weather helps decide how well they do. Some fungi, like the kind that causes panicle and shoot blight, can harm flowers and young branches. Insects such as the leaf-footed bug (Leptoglossus clypealis) also chew kernels and make them smaller. Big outbreaks have hurt farms before, for example in California in the 2000s and in Australia in 2011 when a disease cut many nuts.

Because pistachios need careful water and sunlight, long droughts or cold winters can lower how many nuts a tree makes. Farmers try to protect orchards by planting hardier varieties, watching trees closely, pruning sick branches, and managing water so trees stay healthier.