Needle cast

Asked October 1, 2019, 9:14 PM EDT

We have several large trees close to our home, within feet, that have developed needle cast. Should I plan on having them removed or will they recover in future years? There are so many large old trees around here that have been infected. What might their prognosis be?
I am in Lincoln County which appears to be one of the hotspots for this fungal infection.
Thank you, Cathy

Lincoln County Oregon forestry swiss needle cast douglas-fir

1 Response

Hi Cathy:
Thank you for your questions and concern about your trees. I am sorry to hear that you are concerned about them having a needle cast.

Since you are in Lincoln County, I assume you are talking about Swiss needle cast on Douglas-firs. If this is not the case, we will need to know the species of tree that you have that is having problems.

If you suspect that your Douglas-firs have Swiss needle cast, according to Dr. Dave Shaw, a forest pathologist at Oregon State University who runs the Swiss Needle Cast Collective, you should not have problems as long as your trees are carrying at least three years of foliage. You can check out this PDF on Swiss needle cast for instructions on how to assess the number of years of foliage retention in your trees: http://sncc.forestry.oregonstate.edu/sites/default/files/ForestHealthFS.pdf.

If your trees are heavily affected and have less than three years of foliage retention, I would recommend reaching out to an arborist who can help you assess the extent of the issue and make recommendations for handling potentially hazardous trees.

Should you have any further questions, please feel free to contact me as I am the Extension Forester for Lincoln County and I am here to help!

Thank you.