How to recognise it
Look where two stems of similar size meet. A healthy union shows a raised branch bark ridge that pushes outward; an included union shows a seam or crease running down into the fork, often with bark folded inward. Sometimes a dark line of sap or a crack shows where the weak spot is already moving.
The seam means the two stems are not truly joined. They are leaning on each other, like two people back to back, and the load rises as both get bigger.
Why it matters in Northern Nevada
Siberian elms, Callery pears and many maples here form tight codominant stems. Downslope winds along the Carson Range and heavy wet spring snow put the greatest strain on exactly those unions, and a tree in leaf catches the most. A split often takes half the crown with it.
A repair after the fact is limited. A union that has already cracked can be supported, but the bark inside the fork stays inside. For that reason the better time to act is before a crack shows, and the best time is when the tree is young.
What an arborist does about it
Options run from structural pruning that slows one stem, to cabling, to removing one stem or the tree when the fork stands over a house or driveway. The choice follows the tree's size, the crack, if any, and what it would hit. A certified arborist looks at the whole tree, not only the fork, because root and trunk condition decide whether support is worth installing.
If you hear a crack in a tree during a storm, keep people away from it. If a part falls on a house or a line is involved, the rules are 911 if anyone is hurt, NV Energy for anything touching a line, and then our 24-hour line at 775.232.8243.
Sources
- International Society of Arboriculture, Trees Are Good: Pruning Young Trees (brochure) (read October 17, 2026)