Winter Kill Of Evergreens Throughout Montana

Winter damage is widespread throughout Montana on evergreens this year. The damage consists of tips of newest needles turning yellow, red, or red-brown (Fig. 1). Entire branches might also be affected. The browning is from the outside inward (Fig. 2). The windward sides are most strongly affected.

These symptoms, although they appear alarming, will be less obvious with new growth and dropping of dead needles. As long as the buds are soft and green, there is still good growth and life in the tree.

Winter kill or desiccation occurs when the amount of water lost by the foliage exceeds the amount picked up by the roots. Winter kill and desiccation is also common when there is a large fluctuation in daytime and nighttime temperatures, which occurred on November 12, 2014 throughout Montana. Many cities dropped below -20˚F during the evening.

For management, it is important to make sure your trees are watered throughougly and regularly during dry periods. The brown needles will soon drop.

For more info contact: Laurie Kerzicnik, Schutter Diagnostic Lab, Montana State University, [email protected] or Eva Grimme, Schutter Diagnostic Lab, Montana State University, [email protected]