What's Wrong With My SUMMER GOLD JAPANESE MAPLE - Ask Extension
I have this tree planted in full sun in 8b in Beaverton. 5+' tall. The nursery told me it could likely take it. This is its third summer in this lo...
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What's Wrong With My SUMMER GOLD JAPANESE MAPLE #874509
Asked June 24, 2024, 5:27 PM EDT
I have this tree planted in full sun in 8b in Beaverton. 5+' tall. The nursery told me it could likely take it. This is its third summer in this location. In years past it's experienced leaf scorch in consistently hot late summer. I then put a beach umbrella over it. This summer over the last few weeks (earlier than past years) something a bit different is happening. I'm not sure if it's leaf scorch or what? See attached photos.
Washington County Oregon
Expert Response
Thank you for your question, Linda. Your tree appears to be infected with one of the fungi (very common in the PNW), described here: https://pnwhandbooks.org/plantdisease/host-disease/maple-acer-spp-leaf-spots
Here is what WSU says: https://hortsense.cahnrs.wsu.edu/fact-sheet/maple-phyllosticta-leaf-spot/#:~:text=revision%20date:%202022%2D11%2D,leaves%20by%20water%2Dsplashed%20spores
You may not be able to obtain any of the fungicides listed in either resource, so destroying the effected leaves and avoiding overhead watering may be all you can do before contacting a pesticide treatment company. Good luck!
Here is what WSU says: https://hortsense.cahnrs.wsu.edu/fact-sheet/maple-phyllosticta-leaf-spot/#:~:text=revision%20date:%202022%2D11%2D,leaves%20by%20water%2Dsplashed%20spores
You may not be able to obtain any of the fungicides listed in either resource, so destroying the effected leaves and avoiding overhead watering may be all you can do before contacting a pesticide treatment company. Good luck!
