Plant Disease & Diagnosis Services

diseased leaf

Update (06/25/21):

The UNH Plant Diagnostic Lab will not be accepting samples as of June 1, 2021

As of June 1, 2021, all NH plant diagnostic samples should be sent directly to the University of Maine Plant Disease Diagnostics Lab, and not to the UNH Plant Diagnostic Lab.
Samples submitted to the UNH-PDL after June 1 cannot be processed (and cannot be forwarded to UMaine due to decomposition and loss of quality of the sample in transit).  Submitters will be requested to send new samples to the UMaine Lab.
Please visit the University of Maine Cooperative Extension Plant Disease Diagnostic Lab website for submission forms and contact information.
Commercial clientele should contact the UMAINE lab directly.

Home gardeners should first contact the Extension Education Center
Phone: 1-877-EXT-GROW (398-4769)
This temporary change is necessary due to the retirement of the UNH Plant Health Specialist/Director of the UNH Plant Diagnostic Lab (Cheryl Smith). We are in the process of filling this vacancy.  

We appreciate your patience and cooperation during this time of transition, and appreciate your support for UNH Plant Diagnostic Lab and UNH Cooperative Extension


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 plant material or soil 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