Answer: What you describe sounds like lichen. This is quite common on woody stems and tree trunks or branches in your gardening region. It doesn't look very attractive, but it is harmless to your plants. The only concern is that it might hold too much moisture against the bark and cause rot. Lime/sulfur will kill it and it will weather away or you can peel it off. Lime sulfur is normally used during the dormant season. If you spray it now it can damage the leaves on your plants and tree. I'd wait until late winter to apply it. Best wishes with your landscape!
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