Please help me diagnose deodore cedar tree problem.

Asked June 16, 2017, 1:27 AM EDT

Please see attached photo. This cedar has had similar problems early in the season for the last few years and seemed to have recovered each year. However, it is looking considerably worse at this time with considerably more brown patchy areas. In addition, the shade of green of the rest of the needles seems quite pale. Note: we do notice some new growth. Thank you.

Marion County Oregon trees and shrubs

1 Response

The blight on your Deodar cedar is likely to be a needle blight fungus (of the genus Sirococcus or Kabatina). These kinds of needle or leaf blight fungi tend to be worse with a long wet spring season such as this year's. The spores are dispersed by splashing water at the same time that new growth emerges on the cedars. New growth and twigs near the tip are most affected and trees usually recover later in the summer as you have seen in the past. But this is a particularly bad year.

For more information on the blight and possible treatments, see the article in the PNW Plant Disease Handbook at
https://pnwhandbooks.org/plantdisease/host-disease/cedar-cedrus-spp-needle-blight