Mountain Hemlock shedding needles and dying

Asked July 17, 2020, 4:43 PM EDT

I have a 35' Mountain Hemlock that is shedding needles rapidly and looks to be dying. It is 30 years old that I planted in a grove of 3; one other tree next to it died like this 5 years ago. We live in Sammamish WA which is about 500' above sea level and in foot hills of Cascade Mountains. I have been watering a lot lately to try to rescue, the only thing that I might have done incorrectly lately is that I put a new layer of approx. 2-3 inches of bark around the base in October of 2019. Is this a fungus or something in soil? What would you recommend? Thank you!

King County Washington

1 Response

Hi--from what I can see from your tree, the crown--the very top of the tree-looks good. That pretty much rules out root rot and cumulative drought stress related problems. What's left is needle blight fungal disease. See For homeowners, the only legal control is to use copper-based fungicides. I'm not sure that would help with the size of your tree. My suggestion would be to call an ISA certified arborist--these folks are highly trained and certified to diagnose and treat tree diseases. It would also be a good thing to get confirmation of needle blight. To find an ISA Certified arborist near you, check on this website: