What is causing the odd leaf chlorosis on this red maple? Regardless of what you think is causing the symptom, it's only a guess unless you soil test. Soil tests provide you with information that serves the same purposes as the information that blood tests provide to physicians: soil tests are like a blood test for the soil.
The Elm Yellows BYGL Alert! posted earlier today illustrates another example of the need for soil testing. Is the leaf yellowing caused by a tree-killing disease? Or, is it caused by a treatable condition such as a nutrient deficiency?
You can download a PDF copy of our new soil test by clicking on the link below under "More Information" that's titled "OSU Extension Soil Testing Fact Sheet PDF".