NEW! Corvid-19 Sample Submission Guidelines


The Plant Clinic is devoted to our clients and will remain open until further notice. For the safety of all involved, we request that packages be sent via mail or express delivery if at all possible. If samples are too large to be delivered, please drop them off, with a completed sample form at the West or North loading dock of Cordley hall (map view). Please call us (541-737-3472) to let us know a sample had been dropped off, and we will come get it.

Samples can only be accepted from 10:00 a.m. to 4:00 p.m. on weekdays. Please allow extra time for sample processing.

These measures are being instituted to be in agreement with the University's policies, and to keep our customers and employees safe.  

How to collect, prepare and ship samples

We very much appreciate your cooperation! For best service to your growers, for the most useful returns on your efforts, and for the efficient use of your time, please read and observe these instructions before collecting, packing and submitting specimens.

How to Collect a Sample


  1. Select material showing the symptoms you are concerned about. Send several samples showing various stages of disease, especially early symptoms. If possible also send a healthy plant.
  2. Get all parts of plants, including roots where practical. Enclose roots and soil in a plastic bag. Use another bag to enclose the rest of the plant.
  3. If it is not practical to send the entire plant, include several affected portions of the plant. With stem or branch disorders, also include a section of live material attached to the diseased portion.
  4. If a vascular wilt such as Verticillium wilt or Dutch elm disease is suspected, send several branch sections 1 inch in diameter and about 6 inches long from branches with dying, wilted, or yellowed leaves. Do not send dead wood. Put samples in a plastic bag to prevent drying.
  5. Turfgrass samples should be taken from the edges of affected areas that include dying and also apparently healthy plants. Send one or two 3-by-3-inch squares of sod containing 1 inch of attached soil. Wrap each sample in one thickness of slightly dampened toweling, then in dry newspaper. Send as much information as possible.
  6. Fleshy specimens such as mushrooms, fruit, or potatoes should be as firm as possible and show early and intermediate symptom development. Wrap specimens separately in dry towels or newspaper. Do not put in plastic. Pack with sufficient padding to avoid crushing.
How to Pack and Ship a Sample


  1. Keep plants cool and moist before shipping. Mail as soon as possible after collecting. Mail specimens early in the week to avoid delay in the post office over weekends or holidays.
  2. Pack in a sturdy container to prevent crushing in transit. Use paper to pack the specimen firmly in the container.
  3. Identify the package with labels both outside and inside. Put the label and Plant Disease Form in a waterproof barrier such as plastic.
Mailing Address

Mailing address

Mail to:
OSU Plant Clinic
4120 Cordley Hall
2701 SW Campus Way
Oregon State University
Corvallis, OR 97331-2903
Phone: 541-737-3472