By Judy O’Mara, Diagnostician, K-State Plant Disease Diagnostic Lab
It was pretty cold in mid-January 2024, the low temps in January sent me to the K-State Mesonet (https://mesonet.k-state.edu/weather/historical/) to take a closer look at the weather patterns during that time period. The Mesonet is a collection of weather stations across Kansas that can be used in a variety of ways but my favorite is to take a look BACK in TIME at the historical weather patterns. The temperature dropped pretty low on Jan 14th (-10.5F) and Jan 15th (-10.6F) in Manhattan, KS. Brrr.
In any given year, it is not uncommon to see extreme weather patterns impact plant growth and health. Winter damage to pine trees frequently shows up on the north or northwest side of the tree, although it can hit the top of the tree as well. Winter damage can hit multiple trees or can show up on scattered trees within a planting. The outer needles tend to be scorched with the inner needle growth remaining green. The more exposed foliage is more susceptible to desiccating winter winds. Winter damage on pine trees can be confused with some common Kansas pine diseases such as pine wilt, Diplodia pine tip blight and Dothistroma needle blight. One tip that can help to differentiate between these problems is the TIMING of the damage. Pine trees generally enter the winter looking good and then get hit by low temperatures and/or desiccating winds sometime between December-February. A look at the K-State Mesonet can help pinpoint the weather event that caused the damage.
Winter damage can look pretty dramatic but it is best to wait until early to mid-May to assess recovery potential. Even though the pine needles are scorched, the dormant buds frequently escape damage and push out new growth in the spring. The damaged needles eventually shed and the overall appearance of the tree will gradually improve. Another quick way to check recovery potential is to pop off a few buds at the end of the branch and see if they are still green inside.
Winter damage can be confused with some common Kansas pine diseases. For help sorting out these problems reach out to your local county extension office. The K-State Plant Disease Diagnostic Lab can also provide assistance. https://www.plantpath.k-state.edu/extension/plant-disease-diagnostic-lab/
