Due to lack of resources, Iowa's Big Tree Program is currently on hold. Applications for Big Tree nominations will still be accepted. Processing of the applications will not occur until further notice. Sorry for any inconvenience. Continue looking for big trees.
About the Program
Iowa's Big Tree program is designed to locate the largest tree of various specimens in our state. The purpose is to give special recognition to big trees, focus attention on trees in general, and have to engage in some friendly competition. For information on how to nominate and measure trees for the program and for a list of Iowa's current champion big trees, check out our Big Trees of Iowa document.
Iowa Big Tree List
Criteria for Ranking Iowa's Big Trees
Trees are ranked based on three measurements: circumference, height and crown spread. Ranking is determined by total points.
Circumference: Measure around the tree trunk at 4.5 feet above the ground. If the tree forks at that point, the measurement is made below this where the circumference is least. Circumference counts one point for each inch.
Height: This measurement can be difficult to make, but is important. An estimate of height can be made using a yardstick. First, measure 100 feet from the tree. Next, hold the yardstick vertically, 25" from the eye. Align the zero inch mark on the yardstick at the base of the tree and note the inch mark that aligns with the top of the tree. Every inch equals 4 feet of height. Height contributes 1 point for each foot.
Crown spread: Measure from a point directly below branch tips on one side of the tree to a point directly below branch tips on the other side of the tree. Make a second measurement at right angles to the first. Average the two measurements. Crown spread counts for 1/4 point for each foot.
For more information check out these Tree Measuring Guidlines
provided by The Eastern Native Tree Society
As a starting off point look at this Minimum Tree Circumference Guide
Did You Know?
There is also a National Registry of Big Trees that recognizes champion trees of 826 species and varieties. In fact, Iowa's program is set up using much of the same criteria as the national program. Iowa has one champion on the list: a European Alder in Scott county. For more information on the National Registery of Big Trees visit the American Forests, P.O. box 2000, Washington DC 20013; 202-737-1944.
The 1996 Famous and Historical Trees of Iowa can be found on the State of Iowa Library Services site here: Famous and Historical Trees of Iowa