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Blackened needles on Arborvitae Emerald Green

15 years ago

Hello all,

I'm starting a new post after searching & finding this subject pop up a couple of times in the past but never really be resolved. I was concerned yesterday to find a mysterious black patch on our Arborvitae, which has been in the ground just over a month. The patch looks like it has been spray-painted on but the needles feel normal and I couldn't smell anything. Nothing comes off on your hand, it is like a stain which makes me think it is not soot mold. I saw a few suggestions this is due to animal urine which burns/stains the needles and it is close to the base, so I haven't ruled that out. There are a few stray cats around and this is about the height for a cat to spray. The only related posts I've seen re. this kind of black spotting have been re. Emerald Greens as well but maybe it is the way they react?? Having come across some other "interesting" threads here regarding urine, maybe we should do some spot tests of our own...:-)

But seriously - Has anyone else with EG Arborvitae experienced this, what happened, did it spread, did it just fade in time or is it permanent, etc.? I can try posting a photo. Also the tree is about 7 ft., it is in a somewhat damp patch at the corner of our house and gets about 1/2 day of sun, I thought it would be happy with lots of moisture... we also have that awful red clay soil but it's planted with topsoil and mulched. So, any suggestions?

Point 2 - if we do conclude it is urine, how to repell cats?!

Thank you very much!

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