26 Amazing Oak Tree Facts

By Karin Lehnardt, Senior Writer

Published July 17, 2020

Most likely, oak trees evolved in North America, Europe, and Asia between 40 million and 60 million years ago._[5]
There are about 600 existing species of oak trees._[5]
On average, oak trees live about 200 years, but some can live over 1,000 years._[8]
The Pechanga Great Oak Tree is the oldest oak tree in the United States and maybe even in the world. It is thought to be nearly 2,000 years old._[8]
On average, oak trees reach between 50–70 feet (15–21 meters) in height. They can have a spread nearly 150 feet (45 meters) from branch to branch._[8]

Replacing Notre Dame's oak tree structure could be impossible

During the tragic 2019 Notre Dame fire, the cathedral's oak frame was destroyed. The oak beams were made from trees cut down between 1160 and 1170 AD and form one of the oldest parts of the cathedral. The cathedral's structure contained about 13,000 trees in total._[9]
One oak tree produces nearly 2,000 acorns every year. However, only one in 10,000 acorns will become a full-grown oak tree ._[5]
In 2019, French Prime Minister Emmanuel Macron gifted an oak "friendship tree" to Donald Trump; however, the tree died while in quarantine._[3]
If eaten in large quantities, oak leaves and acorns are toxic to livestock, including cattle, horses, goats, and sheep. The tannic acid in the leaves and acorns can cause kidney damage and gastroenteritis. Only pigs seem to be immune._[5]
Raw acorns contain tannins, which have a bitter taste and can be toxic to humans. However, leaching (soaking or boiling) the tannins makes the acorns safe to eat._[7]
Acorns are an important part of many animals' diets, including birds, small mammals, and larger mammals such as pigs, bears, and deer._[7]
According to Norse legend, the god Thor took shelter under an oak tree, which has led to the belief that an acorn on a windowsill will protect against lightning strikes._[2]

Because of their strength, oak trees are symbols of truth, loyalty, and wisdom

Acorns are nutritious and contain large amounts of protein, carbs, fats, phosphorus, potassium, calcium, and niacin._[7]
Because acorns are rich in fat, acorn flour can spoil or get moldy quickly._[7]
Because acorns only ripen on adult oak trees, they are often a symbol of patience and endurance._[8]
Koreans make edible acorn jelly called dotorimuk._[10]
Druids ate acorns, believing that they had prophetic qualities. In fact, the word "druid" comes from the Celtic word for acorn._[1]

Acorns are also called "oaknuts"

Acorns fall from oak trees, not from acorn trees._[11]
In some cultures, because an acorn is a "baby tree," it is believed that wearing one around your neck will prevent premature aging._[1]
In North America, there are about 90 species of oak trees. All oak trees have acorns._[8]
An oak tree produces about 10 million acorns during its lifetime._[8]
In Harper Lee’s iconic novel, To Kill a Mockingbird, the oak tree outside of Boo Radley’s house is a symbol for friendship and the way kindness can thrive despite difficult circumstances._[6]
The National Geographic Society designated The Emancipation Oak in Virginia as one of the most important trees in the world. In the 1860s, Mary Smith Peake broke the law when she taught African American adults and children how to read under the oaks’ branches._[4]
The national tree of America is the oak tree._[12]
There are nearly 600 species of oak trees. They all fall into two categories: white oaks or red oaks. White oaks have rounded lobe leaves, while red oaks have pointed lobe leaves._[5]
Oak trees can either be deciduous or evergreen. Oak trees are more often evergreens in warmer climates with mild winters._[8]