Ground that lifts or splits beside a trunk can be the visible end of a root failure.

Roots hold a tree up: NC State Extension's gardener handbook counts anchoring the plant and providing "physical support for the stem" among their main jobs, and says a few woody support roots grow downward and outward while most plants have no deep tap root. A Mississippi State University Extension publication the NC Forest Service hosts describes the "structural roots that hold up a tree." A tree stands on a shallow, spreading base rather than a stake, so when it tips, the roots on one side pull up through the soil above them.

The NC Forest Service's storm checklist pairs a newly leaning trunk with "mounding of the soil around the base of the tree on the windward side," the side the wind pushed from and so the side opposite the lean, and asks about cracks in the mound. The USDA guide pictures one such mound with the caption "The mound (arrow) at the base of this tree indicates that the tree has recently begun to lean, and may soon fail." The caption describes the tree in that photograph.

Not every crack in a yard is a root sign. NC State Extension's Durham County Center says of the clay common across the Southeast that "when dry, it cracks and hardens into concrete," so a dry spell can crack a whole lawn with nothing lifted and nothing leaning. The sign on the fence-line check is narrower: ground raised or split at the base of one tree, on one side, and in the sources' own examples it comes with a lean.

The USDA guide's list of root problems opens with severing or paving over roots and raising or lowering the soil grade near the tree. NC State Extension's Union County Center names trenching that severs or tears roots and grade changes adding or removing soil, and its Henderson County Center adds grading equipment and fill dirt over the root collar, where the roots meet the stem.

The Mississippi State publication says such damage usually goes unseen, and that trenching through the structural roots near the trunk "will leave a tree unable to hold itself up." Henderson's center says a tree that survives construction damage is often left structurally unsound and can be prone to toppling in high winds.

The USDA guide also counts parking or driving vehicles over the roots as a root problem, and NC State Extension's gardener handbook says compaction pushes air and water out of the soil's pore spaces and inhibits the movement of roots. Extensive root decay is on the guide's list too, and what fungi at the foot of a trunk can and cannot show is a question for mushrooms at the base of a tree. The guide adds that trees with root problems "may blow over in wind storms"; saturated ground's part in Michael and Fran, and the soil conditions and girdling roots NC State Extension flags, are told in hurricane season in the Piedmont.

The fence-line check lists lifted or cracked soil under Call now, a label it shares with a tree starting to lean; the rest of the check's signs are collected on the hazard tree field guide. The USDA guide's action list for root problems includes "A tree is leaning with recent root exposure, soil movement, or soil mounding near the base of the tree," and it warns that trees with root problems "may even fall without warning in summer when burdened with the weight of the tree's leaves."

A walk-through of this sign reads the ground first: which side is raised or split and how far around the base it runs, any roots newly showing, the lean, and what stands on the far side of the trunk. Storm cases go to the emergency or Monday job tiers.