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dying alder trees #942136

Asked August 11, 2026, 11:35 AM EDT

What is killing all of my large and medium size red alders 35- 75 years old?

Lincoln County Oregon

Expert Response

Hi Andrew: 

Thanks for reaching out to Ask Extension. I am happy to help! 

I'm sorry to hear your red alders are not doing well. What are some of the symptoms you are seeing? 

Are you seeing bleeding sap, ooze, or fungal conks/mushrooms on the trunk or base? Is there canopy dieback starting from the top down or leaf wilting?

Red alders on the Oregon coast are commonly killed or damaged by native root rots, water-molds that produce cankers, trunk-rotting fungi, and environmental stress from drought, wind storms, or fluctuating water tables.

If you have pictures of the damage you are seeing, please send them to my email <personal data hidden>. I am based in Newport and can make arrangements for a site visit also. 

Please do not hesitate to reach out. 

Thank you! 

Dan
Office<personal data hidden>

Dan Stark, Assistant Professor of Practice (he/him) Replied August 11, 2026, 7:08 PM EDT

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