My trees are dying

Asked May 6, 2019, 1:10 PM EDT

We had two beautiful walnut trees in our back yard. Last year the smaller on started to look sickly, thin leafing and no walnuts. This year is is dead. Our other one, more stately and larger one looks sickly this year and is nothing like years past in foliage. What may be happening? Can I save the big one? We live in Sherwood Oregon. All other trees look very healthy. We have plumb, apple, cherry, pear, oak, quaking aspen, popular and others. I've included two photos. The dead one and the sickly larger one. Foliage on the larger one is usually about twice as thick as showing this year. Thanks so much for reviewing.

Clackamas County Oregon walnut trees

4 Responses

Thank you for your question. There are several diseases which cause problems, including death, to walnut trees. However, in order to diagnose which one or ones, we need to examine the leaves and, in come cases, test the soil for soil pathogens. If you can take some leaves from the still-living tree into the Clackamas County Extension office, they can be examined under a microscope to determine if there are fungal spores on them from anthracnose (https://pnwhandbooks.org/plantdisease/host-disease/walnut-juglans-spp-anthracnose), a common problem. The office is at 200 Warner Milne Road, Oregon City, and is staffed 9 to noon, and 1 to 4pm. Note that the office will be closed May 8. Good luck!

  • Thanks so much Kristena. I cut it down today and found the culprit higher up in the crotches of the tree. Thousand Cankers Disease? Here are some quite obvious photos of the damage done. Leaves on the other tree look Normal except small and thinner. Exact presentation as the dead one last year. Is there anything I can spray on the tree to save it, if in fact it's TCD?

  • Thanks so much Kristena. I cut it down today and found the culprit higher up in the crotches of the tree. Thousand Cankers Disease? Here are some quite obvious photos of the damage done. Leaves on the other tree look Normal except small and thinner. Exact presentation as the dead one last year. Is there anything I can spray on the tree to save it, if in fact it's TCD?

Good show! Although I have never heard of it, OSU faculty has studied it and here is Jay’s paper: http://www.science.oregonstate.edu/bpp/Plant_Clinic/Fungicidebooklet/2010/BLACK%20WALNUT.pdf You might want to confirm with him. Thanks!