Container plant samples usually require sending entire plant for diagnosis.

All samples require a Plant Diagnostic Request Form

Sampling Instructions:

  • Examine plants to assess symptoms and distribution. Complete the Plant Diagnostic Request Form with as much detail as possible including site information, pesticide applications, and the symptoms of concern, and include it with the sample in a separate zip-seal bag.
  • Collect a generous representative symptomatic sample that fully describes observed problem. The entire plant may be needed for the most accurate diagnosis, especially with vascular and root rot pathogens. Samples from different plant species should be bagged separately and labeled.
    • Leaf or Stem Samples: place in a zip-seal plastic bag as soon as collected. Include a range of symptomatic plant material. 
    • Entire Plant Samples: Send the entire plant in it's container. Wrap the container and roots in a plastic bag and secure with string or a twist tie to keep soil off the foliage of the plant. Cover the top plant growth with a second plastic bag. 
  • Place the sample in a crush-proof box with sufficient packing material and mail using next-day shipping, or deliver the sample in-person to minimize temperature damage. 
  • Write “Live plant Sample” on the outside of the box
  • Photos of the problem in the field are always helpful and may be emailed to

Mailing Address:
C. Wayne Ellett OSU Plant and Pest Plant Diagnostic Clinic 
c/o Dr. Francesca Rotondo
234 Selby Hall
1680 Madison Ave., Wooster, OH 44691

Sample Drop-off:
Must be coordinated with Dr. Rotondo: Phone: (330-263-3721) | Email: