Rant: got called out by a homeowner in Boise for my collar cut on a 60 foot spruce
Spent 3 days last week on a big spruce removal job in Boise and the homeowner stood on his porch the whole time watching me make every cut, then walked over when I was packing up and pointed at one branch collar that was maybe half an inch longer than the rest. He pulled up some YouTube video on his phone from a guy in Ohio who does it differently and asked me to explain myself right there in his driveway. Do you guys cut flush to the branch bark ridge or leave that little nub, because I have been doing it one way for 14 years and now I am second guessing everything.
Leave the collar. Cutting flush to the trunk is what kills the tree and lets rot in, the nub is there for a reason. Homeowner watched too much YouTube and now he thinks he's an arborist, you did it right for 14 years, don't second guess it over some guy in Ohio.