Many aspen, cottonwood leaves dying early

Sep 10, 2015

Marssonina leaf spot, caused by the Marssonina fungus.
Credit W. Jacobi/Colorado State University

The Colorado State Forest Service says certain trees will be less colorful this fall. A wet spring and summer have been ideal conditions for at least two kind of fungus that are affecting aspen and cottonwood trees across much of Colorado.

  The fungi look like leaf spots, making leaves look darker than usual. The state’s Forest Service says a significant number of those trees in the Roaring Fork Valley are affected. That came to light during recent aerial surveys of forests. Some trees with the fungi have already dropped their leaves. Scientists say any remaining leaves will fall off at the very beginning of the fall colors.