TL;DR
A branch collar is the swollen ring of trunk tissue at the base of a limb where trunk and branch wood interweave, containing the chemically protective zone a tree uses to wall off decay after a limb is lost. Proper pruning under ANSI A300 cuts just outside it, leaving the collar intact, never flush to the trunk and never leaving a protruding stub.
What it means
A branch collar is the swollen ring of trunk tissue at the base of a limb where trunk and branch wood interweave, containing the chemically protective zone a tree uses to wall off decay after a limb is lost. Proper pruning under ANSI A300 cuts just outside it, leaving the collar intact, never flush to the trunk and never leaving a protruding stub. A correct cut closes in a neat ring of callus over a few seasons; flush cuts open the trunk to decay columns that surface as cavities years later. Spotting whether old cuts respected this ring is a quick way to judge a tree service's past work.
Where it sits in the glossary
Branch collar is part of the Trade jargon group inside the ProFix Directory glossary. Browse every term in this category from the glossary index.
Why Ohio homeowners should know it
This is a term Ohio homeowners encounter when reading contractor quotes, hiring paperwork, or inspection reports. Understanding it well enough to ask one good follow-up question is usually all the protection a homeowner needs.
ProFix Directory keeps definitions short on the index page and saves the longer context — Ohio-specific rules, where the term comes from, and which ProFix tools touch it — for these per-term pages so the term is easy to cite and easy to share.
ProFix tools that touch this term
See also
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