Aspen Tree Blight

Asked April 24, 2015, 6:36 PM EDT

My aspen tree is leaking a brown fluid from the joint where the limb joins the trunk. This blight is affecting other aspens in the Alta WY area. Do you have suggestions on how to treat this blight? (I live in Alta - west side of Tetons, Teton County Wyoming)

Teton County Wyoming

1 Response

From the picture it looks like you are not dealing with a blight, but rather an insect problem. The trees look like they are now hosting a poplar borer. The brown sap/stain you see is the trees defense mechanism against the borer. Poplar borers are quite common in Aspen, but also can be difficult to control because they are located in the heartwood of the tree. Utah State University has a good bulletin on Poplar Borers including control methods. Here is the link. https://extension.usu.edu/files/publications/factsheet/poplar-borers01.pdf