Red cedar death update?

Asked January 29, 2020, 3:38 PM EST

Greetings! We live on Bannister (flows into Bronson) Creek west of Portland and we have 30-50 year old Red Cedar trees that are dying at the edge of the creek. There are small areas on the trunk exuding clear pitch. Top turning brown but almost seems that the stress causing lowermost limbs to grow with vigor. The pitch spots seem to suggest borers. Is there a known cause of Red Cedar in the area dying? And if so is there anything we can do? Thank you for your time, Catherine Glass

Multnomah County Oregon

1 Response

Western redcedar decline has been an increasingly common problem in our area, most likely due to climate stress, particularly on certain soil and site situations. But we do not know specific causes with certainty. The heat and drought episodes over the last 5 years have been relatively severe compared to the last 50 years, which we think is the main trigger for decline in various species including redcedar.

In some cases, a tree with top dieback can survive and sprout a new top from below the extent of the top dieback. However, most cases I have seen with major top dieback (>50%) in the Willamette Valley and foothills end up with the whole tree dying within the next year or two. See the information sheet on dying western redcedar at

Also, wood borer beetles are commonly found in the dying cedars, but these are not considered to be the primary cause, just the secondary pest moving in on a declining tree. See the article at

Along with the Oregon Dept of Forestry, we are collecting location specific data on dead and declining redcedar trees, for possible monitoring and research. It would be great if you could email me back (address below) with your contact information, address, and the number of trees that are dead or symptomatic.