Frequently Asked Questions

Q. How do you determine a national champion?

A. To calculate a tree’s total point value, American Forests uses the following equation: Trunk Circumference (inches) + Height (feet) + ¼ Average Crown Spread (feet) = Total Points.

A nominee will replace a registered champion if it has more points. When two trees have scores that fall within five points of each other, they are listed as co-champions. Champions listed in the registry must be re-measured every 10 years to maintain their champion status.

Q. How often is the National Register of Big Trees updated?

A. The National Register is updated twice a year in the spring and fall on American Forests’ website. The register is published as a printable PDF every two years. View the current register.

Q. How do I nominate a tree?

A. Learn more about how to nominate a tree and what is required for each nomination.

Q. What species are eligible for the National Register of Big Trees?

A. There are more than 870 species and varieties eligible for the National Register of Big Trees. These species must be recognized as either native, non-native, naturalized or a recognized naturally occurring variety in the United States. Hybrids and minor varieties are excluded. American Forests has based this list on sources such as the USDA Plants Database and the Integrated Taxonomic Information System (ITIS).

View the list of eligible species.

Q. How can I add a species to the National Register of Big Trees?

A. Additions to the species list for the National Register of Big Trees should be submitted to American Forests by January 1st for the spring register and July 1st for the fall register. These species must be recognized as either native, non-native, naturalized or a recognized naturally occurring variety in the United States. Hybrids, cultivars, ornamentals and unclassified varieties are excluded. Nominations for new species must be recognized in the USDA Plants Database. Nominate a new species.

Q. What is a native, non-native or naturalized tree?

A. View the glossary for a complete list tree of definitions.

Q. What is the difference between a tree and a shrub?

A. Trees are woody plants that have one erect perennial stem or trunk at least 9 ½ inches in circumference at 4 ½ feet above the ground. They also have a definitively formed crown of foliage and a height of at least 13 feet. In contrast, shrubs are small woody plants, usually with several perennial stems branching at the base.

Q. How do I identify a tree?

A. Every state has a big tree program that lists state champions. The state coordinator for your respective state will be able to assist you in identifying and measuring your tree. Find your state coordinator in our directory.

Q. Does my state have a big tree register?

A. All fifty states, and the District of Columbia, have their own registers. Find your state program in our directory.

Q. Can I visit a national champion? If so, how do I find its location?

A. Many of our champions are located on public land (such as national forests or national and state parks), where you can visit them. However, if a tree is located on private land, we ask that you respect the landowner and ask permission before making a visit. You can learn more about the specific location of trees by contacting your state coordinator.