May 29, 2009

Dead eastern redcedar trees are showing up in windbreaks in an area from southwest Hastings to north of Columbus. The trees died this spring, probably from very cold temperatures in March. (IANR Photo)

The dead trees mostly are in windbreaks in an area from southwest of Hastings to north of Columbus and are mostly younger trees under about 10 feet tall.

A Nebraska Forest Service forest health expert and UNL Extension officials examined many of the trees earlier this month. They believe a sudden freeze in early spring is the likely cause of the problem.

"We've seen some long windbreaks where as many as two-thirds of the cedars died over the winter," said Mark Harrell, Nebraska Forest Service forest health program leader. "When something like this happens over the winter to a large number of trees, it's almost always caused by a sudden, large drop in temperature."

Harrell said other factors, such as stress from the recent drought combined with root damage from disease-causing fungi in the soil, have been killing smaller groups of trees at some locations, but a freeze injury is the most likely cause where large numbers of trees are affected at this time of year over a wide area.

"We saw no evidence of any significant disease or insect problem on the foliage or anything that could be controlled with a pesticide treatment, so there's no reason to spray the trees to try to control anything," Harrell said.

It would be good to wait a few weeks to see if some of the brown trees grow out new foliage, Harrell suggested, because it is possible that the freeze killed only the foliage, and the branches may grow new foliage if given enough time.

The Nebraska Forest Service is a part of the Institute of Agriculture and Natural Resources at UNL.

Becky Erdkamp, Education and Outreach Specialist
Nebraska Forest Service