Greenhouse flats or container plant(s)

All samples require a Plant Diagnostic Request Form

Sampling Instructions:

  • Examine plants to assess symptoms and distribution. Complete the Plant Diagnostic Request Form and include it with the sample in a separate zip-seal bag.
  • Collect a generous amount of representative symptomatic fresh plant material, or multiple plants (seedlings) that fully describe observed problem. Samples should represent the early to middle stages of the problem. A mixture of living tissue and necrotic tissue is needed to isolate the pathogen and diagnose the disease. Do not send dried or dead plants.  Samples from different plant species should be bagged separately and labeled.
    • Leaf or Stem Tissue Samples: place in a zip-seal plastic bag as soon as collected.
    • Fruit Samples: Separate fruit samples from roots and top growth material. Fruit with tender skin (strawberries, blueberries, currants, raspberries, peaches etc.) should be placed in a paper bag as soon as collected. Fruit with a tough skin (grapes, apples, plums, etc.) can be placed in zip-seal plastic bags.
    • Entire Plant/Tree Samples: Place roots in a plastic bag and seal at the soil line with a twist tie or a rubberband. Do not cut the root ball off the above-ground plant parts. 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 or two-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 may be emailed to The environmental conditions of the plant can play an important role in the diagnosis.

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: