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Diagnostic Lab

Henrico County Master Gardeners operate a diagnostic service for solving plant pest and disease problems. Plant samples may also be submitted for simple identification. The service is offered during the growing season (April thru October) 9 a.m. – 1 p.m. every Wednesday and Thursday.

It is possible to diagnose many problems by looking at pictures. You can send pictures of your plant pest or disease to  You can also submit your question with photos to Ask an Expert.

If it is determined that you must bring in a sample, please follow the following procedures:


1. Collect and Pack Sample

  • For plant disease/problem diagnosis: Provide a sample showing both diseased and healthy tissue. Samples should have stems or branches at least 6″ long. Include a small handful of roots if the plant can spare them. Pack the sample material in sealed, clear plastic bag(s), if possible.
  • For simple plant identification: Provide as many parts of the plant as possible – the entire plant if it is small enough. Include stems, leaves, flowers, and berries/fruit (if available). Pack the sample material in sealed, clear plastic bag(s), if possible.
  • For Insects: Collect one or more complete insect specimens and place them in a sturdy plastic container, such as old pill bottle, with diluted rubbing alcohol. Soak insects overnight to preserve them, then drain off ALL the alcohol and seal. Do this BEFORE you bring in the sample.

2. Submit Sample
Call the Henrico County Extension Office at (804) 501-5160 to make an appointment to drop off your sample. Bring your sample to the Henrico County Extension Office, Henrico Human Services Building, 2nd Floor, 8600 Dixon Powers Drive, Henrico VA 23273.

Complete the Diagnostic Form to the best of your ability (Download Form here). It includes your contact information and simple questions and answers for either Plant or Insect.

3. Receive Results
Your sample will be analyzed at the Lab and a detailed diagnosis with recommendations will be emailed or mailed to you. This may take 2 – 4 weeks, depending on the time of year and the backlog of requests.