Some trees are carbon-dated to determine their ages. This dating method works well for trees that live in climates without great weather fluctuations. If the carbon in the middle of the tree remains in the same area from early growth to maturity, then this dating method can be valid. However, as Conifers.org points out, trees such as palms "do not have a single definable area of their trunk that dates to the tree's early years."
The general rule for telling the age of a tree is to count the rings on its trunk. However, this rule doesn't work for the palm tree. Indeed, the lack of easily identifiable markings on its trunk makes the palm a challenging tree to date. The best way to determine a palm tree's age is to investigate its history. The life spans of palms are dependent on the type of palm. For example, green thatch palm's life span is about 150 years while an oil palm's life span is only about 25.
Research the history of the palm tree you want to date. This is easier if the palm tree is on a protected site, such as a national park. A park ranger or a horticulturalist on site may be able to help you identify how old the palm tree is.
Look up the species of the tree using resources at the library to get a general sense of the lifespan of the palm tree.
Determine if the tree has gone through a radiocarbon dating process. A national park service representative might be able to tell you if this information is available. Radiocarbon dating is a scientific process that measures the tree's growth rate by analyzing it with chemicals. This is a contested method--and one that's used sometimes for dating palm trees--because it takes the tree's growth rate over a certain time span and infers this rate for the lifespan of the plant. This method, however, doesn't take into account factors that can inhibit growth at any given time, such as climate or disease.
Vera Leigh has worked as a professional freelance writer since 2008. Her work has appeared in "Learn Overseas" and "Grad Source" magazines. In addition, she received an honorable mention in "Newsweek's" My Turn contest. She has written features for nonprofits focused on literacy, education, genomics and health. In her spare time, Leigh puts her English major to use by tutoring in grammar and composition.