The WSU Pullman Plant Diagnostic Clinic is closed as of December 1, 2025. For alternative diagnostic support, please contact your local WSU Extension specialist, Master Gardener Coordinator, or other diagnostic resources, such as:
- WSU Puyallup Plant & Insect Diagnostic Lab – Jenny Glass (jennyglass@wsu.edu,253-445-4582)
- Oregon State University Hermiston Plant Disease Clinic – Dr. Ken Frost or Cassandra Funke (cassandra.funke@oregonstate.edu, 541-567-8321 ext. 120 or (Kenneth.Frost@oregonstate.edu)
- University of Idaho Parma REC Diagnostic Lab – Dr. James Woodhall (jwoodhall@uidaho.edu)
- Richard Old, Weed Identification (rold@pullman.com)
If you need further assistance, please contact Melissa Bills, Administrative Manager for the WSU Department of Plant Pathology (melissa.bills@wsu.edu, 509-335-4852) or Dr. Lindsey du Toit, Chair of the Department of Plant Pathology (dutoit@wsu.edu, 360-848-6140).
Please complete a Turf Grass Submission Form (pdf) and submit with the sample!
Commercial turf problems (golf courses, sod farms) are handled at the Puyallup clinic.
All other turf problems: Collect samples of turf cores that are at least 4 inches by 4 inches square and 3 inches deep. Include roots, thatch, and soil. Place each turf core into a plastic bag. Sample should be moderately moist but not saturated with water. Please include cores displaying the range of symptoms present at the site.
If insects may be involved, include specimens of the suspect insect according to instructions for submission of insect samples.
Sending Samples
Clinic USPS mailing address:
Washington State University
Plant Pest Diagnostic Clinic
Department of Plant Pathology
P.O. Box 646430
Pullman, WA 99164-6430
UPS and FedEx address:
Washington State University
Department of Plant Pathology
Plant Pest Diagnostic Clinic
100 Dairy Road
Pullman, WA 99164
Please do not mail on a Friday or before any national holiday because the specimens may deteriorate over the weekend.