Die off of multiple big leaf maples and ash trees

Asked March 19, 2020, 6:57 PM EDT

Hello - I wish to understand the cause of a die-off of multiple big leaf maples in my yard and neighbors yards. I have a 1/4 acre lot in SW Porltand with a nice stand of firs, adjacent to the firs is a stand of big leaf maples. Last year I noticed half of these maples are dead. - all the dead ones are no bigger than 8" in diameter. This spring I see branches in the others that indicate they are in bad shape also. The trees range from 6-8" in diameter to 18-20" in diameter. Lots adjacent to mine also have multiple maples which are dead or dieing. There are a few ash trees interspersed among these maples and they seem to be in bad shape too. One ash that's probably 25" in diameter is full of holes about 1.5 stories up into the tree. Another ash on my lot that is separated from other trees also has dead branches and several holes in the trunk. I don't know if the holes are made by woodpeckers or squirrels but a couple are occupied by birds now. So - what might cause this relatively quick - over 2 years - die off? I am really concerned about these maples now, especially the larger ones. I want to replant some kind of trees - but should i wait for a time in case some kind of pathogen killed these? I don't normally water these trees as they seem to get enough on their own. I am wondering if the last 2-3 years of dry weather from July into Oct did them in? Thanks for your help and expertise. Lynn

Multnomah County Oregon

1 Response

Hi Lynn,

Thanks for your question. Sometimes it's hard to tell what's going on when we can't see it for ourselves. Would it be possible for you to respond and upload photos of the trees that seem to be having an issue?