Winter Injury

For information on winter injury, please see the article Browning of Evergreens, Winter Damage on Trees

Type of Sample Needed for Diagnosis and Confirmation

The first and most important step for managing a tree disease is accurately diagnosing the problem. The best approach to diagnosing tree problems is to start by submitting photos of the tree.

General pictures of the tree (location, whole plant appearance) and specific ones (twig, leaves and trunk close-ups, canker or cracks, in limbs and the base of the plant, etc.) would be appreciated. See our guidelines on taking and sharing photos on our page.

If you suspect winter damage, starting with photos is the best alternative, as it is impractical to collect a physical sample, as there are no tests we can conduct in the clinic that confirm that is the case.

Concerned about conifer diseases? 

See the interactive conifer disease key to help you determine what your problem might be and what type of sample is necessary for diagnostics. 

The Iowa State University Plant & Insect Diagnostic Clinic can help you investigate and confirm if your plant has this disease. Please see our website for current forms, fees, and instructions on collecting and packing samples. Contact information for each state's diagnostic laboratory for U.S. residents can be located on the NPDN website.  If you have a sample from outside of Iowa, please DO NOT submit it to the Plant & Insect Diagnostic Clinic without contacting us.


Image of winter injury on a pine tree
Winter injury on a pine tree 
Last reviewed:
May 2022

Links to this article are strongly encouraged, and this article may be republished without further permission if published as written and if credit is given to the author, Yard and Garden, and Iowa State University Extension and Outreach. If this article is to be used in any other manner, permission from the author is required. This article was originally published on September 1, 2016. The information contained within may not be the most current and accurate depending on when it is accessed.