08/31/2026
Today's hot topic, Included branch unions. What are they? How to identify them? What hazards do they pose? And what to do about them?
Included branch unions, or trunk unions, are where 2 branches or stems of the trunk grow closely together side by side untill they literally grow into each other.
You can identify this structural defect by clearly seeing 2 branches or trunks growing very close to one another almost parallel and close to their originating point you will see a defined line that doesn't look like an open crack. Just a line where the 2 branches can be separately identified but they're clearly smashed together.
This type of union is very hazardous as it grows because the 2 stems force against each other and push each other apart and rub each other bark and cambium away over time creating a large wound that moisture, fungus, and bacteria can get inside and set up and begin to rot the wood causing a structural defect and a huge hazard for the weaker side to break off. This defect is very common in soft wood trees such as maples, hackberry, and callory pear aka Bradford pear.
What do do about this you might ask? Well it's best to identify this structural defect early and get a corrective prune job done to eliminate one of the 2 repeating branches. We call this subordination. If however it gets larger and the branch can't safely be removed without harming the health of the tree or causing a massive visual defect and making your tree extremely ugly then some pruning, cabling, and bracing along with fungicide and pesticide treatments might be in order order. If you see this defect call us and let us come out and evaluate your situation and help you best identify a solution that fits your needs. (479)789-3307