Plant Disease & Diagnosis Services

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Due to the public health concern caused by the COVID-19 virus, UNH administration made the decision to close all University offices and adjust diagnostic services until further notice. We appreciate your understanding and patience during this uncertain time.

Walk-in and mail-in samples will no longer be accepted for any diagnostic service until further notice. (Samples received after March 17 will be processed when services resume)

Online Service

For home gardeners:

Ask UNH Extension staff will answer soil,plant and insect questions on the phone at 1-877-EXT-GROW (398-4769), via email at, and Twitter, Facebook, and Instagram.

For commercial producers/operations only:

  • Soil samples: In the absence of a soil test, commercial growers should refer to previous soil tests, home gardeners follow guidelines recommended in our factsheets for fertilizing vegetable gardens or fruit trees. If you have misplaced your old soil test, contact Soils already submitted to the lab will be processed when services resume.
  • Plant samples: The Plant Diagnostic Lab is accepting digital samples sent by email to Submissions must include your name, phone number, business name, county, host plant, problem, date when symptoms were noted and good, in-focus images.
  • Arthropod samples: Our staff are accepting digital samples sent by email to Submission must include your name, phone number,business name, county, where you found the specimen and good, in-focus images.


The diagnostic services offered by the UNH Plant Diagnostic Lab include identification of plant pathogens, stress-related disorders and pests. The UNH-PDL is directed by the Cooperative Extension Plant Health Specialist and serves as a resource for information and examples for training and educational programs offered throughout New Hampshire and the New England region.

Detailed information about the available diagnostic services, prices, and instructions for collecting and submitting your plant sample can be found on the Submit a Plant Sample for Diagnosis page below.

*ATTENTION: Campus construction starting 5/20/19. Please see location, hours, and contact information below for drop-off information. 

Download the submission form

Location, hours and contact information.