Plant Disease & Diagnosis Services

diseased leaf

Update (03/26/21):

The UNH Plant Diagnostic Lab is now open for mail-in samples only.

Due to COVID-19 the UNH Plant Diagnostic Lab (UNH-PDL) will only be accepting samples by mail until further notice. Your safety and the safety of our students, faculty and staff are our highest priority. Please do NOT drop off a sample to the Durham campus.

Please mail samples early in the week. Instructions for submitting samples can be found here. The UNH-PDL sample submission form can be downloaded here: Please include the form and payment with your sample.

Please be aware that although we will be processing physical lab samples, UNH-PDL staff continues to work remotely the majority of the time. For questions about submitting samples to the UNH-PDL please leave a message for Cheryl Smith (UNH Plant Health Specialist) at 603-862-3841, or Shyloh Favreau at 603-862-3200, or email

Please mail all Plant Diagnostic Lab samples to:

UNH Plant Diagnostic Lab

G37 Spaulding Hall

38 Academic Way

Durham, NH 03824


Detailed information and instructions for collecting and submitting your plant sample can be found on the Submit a Plant Sample for Diagnosis page.


The diagnostic services offered by the UNH Plant Diagnostic Lab include identification of plant pathogens, stress-related disorders and pests.


Please note: The lab is not able to test for pesticide residues or other contaminants.


The UNH-PDL provides diagnostic services for plant health issues to commercial producers and home horticulturists, landscapers and turf managers, arborists, and others in agriculture and the allied green industries.


The UNH Plant Diagnostic Lab will email (or send) a written report when a conclusion has been reached on the diagnosis or identification of the problem. Management recommendations (if applicable) will be included with the report. E-mail responses will come from Please be sure that e-mail from this address is not marked by your server as spam. All results are confidential.


The UNH-PDL is directed by the Cooperative Extension Plant Health Specialist and serves as a resource for information and materials for training and educational programs offered throughout New Hampshire and the New England region.


Download the submission form