Armillaria Fungus help - Ask Extension
We have an infestation of honey mushrooms! I'm pretty sure they are what killed the Big Leaf Maple in our front yard a few years back, they are curren...
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Armillaria Fungus help #607274
Asked November 24, 2019, 2:41 PM EST
We have an infestation of honey mushrooms! I'm pretty sure they are what killed the Big Leaf Maple in our front yard a few years back, they are currently fruiting under a small Salmonberry bush that is probably in the root path of the dead tree (since cut down, but there was no way to remove the stump). Somehow that have managed to travel all the way to the backyard and are now fruiting on/under and attacking our Pacific Willow tree. We live in a fairly dense urban neighborhood in North East Portland and I am very concerned about this fungus killing all the trees in our neighborhood. Is there anything that can be done about this?
Multnomah County Oregon
Expert Response
Thank you for your question. The mushrooms you are seeing are only the visible part of a fungus that is in the soil, and which breaks down susceptible plant tissues near it. So, the mushrooms aren't the cause, they're related to the real "culprit," Armillaria fungus. Here is an Extension article which explains what it is (above and below ground), and what does and doesn't work to 'control' it: http://extension.cropsciences.illinois.edu/turf/diseases/armillaria/
The bottom line is that, once the fungus is as established as it is near susceptible trees such as willows, there is not a lot you can do. Long term, you may have to bring in an arborist to assess whether the trees pose a danger to homes and animals, including humans. BTW, maple trees are immune from this fungus, so your loss of the big leaf maple may be another pathogen such as verticillium wilt (http://hortsense.cahnrs.wsu.edu/Search/MainMenuWithFactSheet.aspx?CategoryId=1&SubCatId=5&Pl...)
Hope this is helpful. Good luck!
The bottom line is that, once the fungus is as established as it is near susceptible trees such as willows, there is not a lot you can do. Long term, you may have to bring in an arborist to assess whether the trees pose a danger to homes and animals, including humans. BTW, maple trees are immune from this fungus, so your loss of the big leaf maple may be another pathogen such as verticillium wilt (http://hortsense.cahnrs.wsu.edu/Search/MainMenuWithFactSheet.aspx?CategoryId=1&SubCatId=5&Pl...)
Hope this is helpful. Good luck!
