The Bennett Juniper of California is estimated to be 3,000 to 4,000 years old; the largest known juniper in the world has a hollow trunk that hides its exact age |
California’s Stanislaus National Forest is home to the Bennett Juniper, a spectacular tree known for its large trunk and age. It is the largest known example of a Sierra juniper, described as the largest juniper species in the world.
The tree is 24 meters tall and has a trunk diameter of 389 centimeters.According to the Journal of the California Native Plant Society, Fremontia, the juniper is at least 2,200 years old, although its exact age is unknown. Its bare trunk prevents researchers from obtaining a complete tree-ring record. Despite these limitations, available evidence confirms that the Bennett Juniper has lived for a thousand years, making it a unique example of ancient California trees.
The largest juniper in the world grows in the Sierra Mountains
Sierra juniper, scientifically known as Juniperus grandis or Juniperus occidentalis var. australis, depending on where it comes from, is the largest juniper species in the world. Bennett Juniper is an excellent example of this. It grows on a private reserve within the Stanislaus National Forest in Tuolumne County.The Bennett Juniper stands 24 feet tall, and its trunk measures 389 inches in diameter. Robert Van Pelt notes that decades of searching the Sierra mountain region have failed to find another juniper of equal size. Sierra junipers often grow on rocky cliffs and other harsh terrain where trees struggle to survive. The Bennett Juniper, however, grows in a stream, making its location unusual for a Sierra juniper in the high Sierra mountains of California.
PC: Journal of the California Native Plant Society, Fremontia
Bennett Juniper’s journey from historic site to protected tree
People may have known about the Bennett Juniper for centuries before it appeared in written records.
American bedrock poles and obsidian deposits found nearby suggest that people used or visited the area long before Euro-Americans recorded the tree.The first mention of it dates back to the 1920s, when shepherds told naturalist Clarence Bennett about it. Bennett studied junipers and became a vocal advocate for protecting the tree. In the 1950s, the US Forest Service named it in his honor.
Today, the Bennett Juniper is protected by the ‘Save the Redwoods League’, helping to preserve the tree for future generations.
PC: Journal of the California Native Plant Society, Fremontia
The challenge of determining the age of Bennett Juniper
Researchers have tried more than once to find out the age of the Bennett Juniper. Dendrochronologists, who study tree rings, took samples in the 1930s and again in 1989. However, the trunk is empty, which makes it difficult to get a complete record and get the full age of the tree. Researchers were still able to conclude that it is at least 2,200 years old.That estimate is less than the exact age, and because the trunk is hollow, the full age of the tree cannot be known. Van Pelt notes that the oldest recorded juniper in the world is another Sierra juniper, the Scofield Juniper, located 10 miles away. Its average age is 2,675 years, although its trunk size is less than half of the Bennett Juniper.
Point system
Determining which is the tallest tree is not as easy as measuring its height.
A short tree with a thick trunk may be larger in general than a tall, thin one. To compare trees consistently, American Forests developed a scoring system for its National Register of Large Trees, based on three measurements: trunk circumference at breast height, tree height, and average crown spread.The system awards one point for each inch of trunk circumference and each foot of tree height, with an additional point for every four feet of average crown spread. When the registry was established in 1941, it listed 77 trees from 24 states. It has since grown to nearly 800, helping researchers compare the largest trees and document the size of hard-to-see species.
