Chlorotic willow oak
You can submitt 7-8 leaves, healthy and chlorotic in a plastic bag , to our office (address below) 8-4:30 Monday - Friday. I would also suggest a soil sample, about a pint of soil, from around the drip line. Fertility and/or pH may be a factor. You can drop off both samples at the location below.
Let me know if you have further questions.
ANR Agent/County Coordinator
Jefferson County Extension Office
4200 Gardiner View Ave, Ste 101
Louisville, KY 40213