Guidelines for Collecting and Submitting Plant Material to the Plant Diagnostic Lab

All samples should be accompanied by a Submission Form. Please provide as much material as possible about the specimen & the problem you are submitting it for.

  • What is the host plant?
  • When was the plant planted/transplanted/purchased?
  • What the problem is?
  • When the problem was first noticed?
  • Describe the symptoms.
  • What pesticides and/or fertilizers were used on or near the plant (fungicides, insecticides, herbicides, fertilizers)?

If possible, send/submit entire plants for diagnosis (if the whole plant is exhibiting symptoms). Submit several plants or plant parts that exhibit a range of symptoms (healthy, moderate, severe). Plants cannot be returned to the sender/submitter after diagnosis is complete.

Avoid mailing samples at times when they will remain in the Post Office over weekends (mail no later than Wednesday) or holidays. All packages should be marked 'hand cancel'.

Whole plants:

Small plants should be dug, not pulled, from the soil. Shake the excess soil from the roots and wrap the root ball in a plastic bag. A second plastic bag with holes punched in it may be loosely placed over the foliage to reduce drying. Do not water the plants before submitting. Place the plants in a box and pack securely with newspaper.


Collect leaves when the foliage is dry. Press the leaves between two sheets of DRY paper or paper towels and then between two pieces of cardboard or stiff paper.

Twigs, Branches & Stems:

Select samples to include the 'transition zone'. This includes the area between the affected area of the branch and the healthy area of the branch. Wrap the cut end of the branches or twigs in a moist paper towel then follow the paper towel with a plastic bag.


Cut a 6-8" square (minimum), 2-4" deep (or deeper if thatch is excessive). Sample from the border of healthy and diseased (or symptomatic) turf (Include both healthy and symptomatic turf). Keep the sample cool, and do not wet the sample. Wrap the sample in several layers of aluminum foil and place in a box and pad with newspaper.

Roots, Fruits, Vegetables, Tubers, etc.:

Select samples that are in the early stages of disease or decay. (severely rotted specimens cannot be diagnosed). Wrap the sample in DRY paper towels and enclose in a plastic bag with holes punched in it. Pack securely with newspaper in a crush-proof box. It is best to submit these samples directly to the UNH-PDL or send the samples overnight mail.