Mature Cedars suddenly turning brown #232039 - Ask Extension


Mature Cedars suddenly turning brown #232039

Asked March 20, 2015, 3:53 PM EDT

We just moved onto a property with two ceaders, planted about 10 feet from each other, one with about an 8 inch diameter trunk and the other with a 12 inch diameter trunk at the base. They looked great until a few weeks ago, when the foliage began turning brown. It has gotten rapidly worse. I can't think of anything we have done that would have impacted the trees. The soil doesn't seem waterlogged. It seems odd that they would die shortly after we moved in (4 months ago), and that it is happening so suddenly. I am hoping maybe you can help troubleshoot what the problem might be, and if I can save these trees. There is some kind of bug on the underside of all the leaves, and even the green leaves look sick.

Marion County Oregon

Expert Response


These cedars look like Port Orford Cedar, also known as Lawsons Cypress.  That is important, as there is a common killer of Port orford cedar known as POC root disease (Phytophthora lateralis).  This disease can kill cedar, and it can be sudden.  If you google Port Orford Cedar Root Disease FIDL, you will find some good info on this disease, but the bad news is that there really isn't anything one can do once the trees are infected.  So the question is whether these are POC or western redcedar.  The cones will tell you.  Cones of POC are round, while western red cedar are elongated and have flat cone scales.  You did not cause this mortality, it is quite a coincidence I think.  The disease can be transported on car tires, or splash from trucks etc due to its persistence in soils.

David Shaw Replied March 20, 2015, 4:23 PM EDT

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