Plant Pest Diagnostic Clinic

The Washington State University Plant Pest Diagnostic Clinic is dedicated to serving the state of Washington and its citizens through high quality service by providing plant disease and disorder diagnosis, pest identification, and management strategies. The Plant Pest Diagnostic Clinic provides plant health problem diagnosis to homeowners; greenhouse and nursery operations; public and private landowners; and commercial growers including those involved with agriculture, horticulture, and floriculture.


To submit a sample for Diagnosis, please fill out a submission form (pdf) and follow the sample guidelines.

Please Note: Hemp samples MUST be accompanied by a Washington State Hemp Producer’s License


To submit a sample for virus testing, please fill out a Virus Test Submission Form (pdf).

To submit samples for Little Cherry Virus and Western X, please fill out a Little Cherry Disease Response Diagnostic Request form (pdf).

Please Note: We are currently accepting samples for Little Cherry and Western X testing. Cost for testing is $50/test/sample.  

Clinic Locations

Washington State University operates two Plant Pest Diagnostic Clinics, in Puyallup and in Pullman. Services of either clinic are available to clients statewide; samples from eastern Washington are usually submitted to Pullman.

To send a sample from a state other than Washington, please contact the clinic prior to submission. Out of state samples will be charge double the service fee.

Please Note: We cannot accept cannabis samples due to WSU compliance with Federal policy.

Shipping Information

Clinic USPS mailing address:
Plant Pest Diagnostic Clinic
Department of Plant Pathology
P.O. Box 646430
Pullman, WA  99164-6430

Clinic UPS and FedEx address:
Plant Pest Diagnostic Clinic
Department of Plant Pathology
410 Dairy Road
Pullman, WA  99164