The plant to be treated must be on the label for a legal application. A color brochure from the Ohio Nurserymen's Association having the most common disease and insect problems of landscape plants is Reference Woody.4. Assistance with diagnosis is available through the Plant Pest and Disease Clinic on the Columbus campus of The Ohio State University. The current forms, instructions for use and fees are on file in Extension offices. You may use this service and you should encourage clients to use it.
Diagnosis is handled differently in each office.
Check with the horticulture or agriculture agent for current procedures. For problems on valuable trees, the service of a certified arborist is always recommended.