How to recognise it
Signs include a flat or sunken side at the base of the trunk, a missing root flare on that side, a root that curves back toward the trunk, and a crown that is thin or dying on the same side as the root. Some are visible only when the soil is moved. On a fast-growing tree the damage can build for years before the crown shows it.
Girdling roots often start when a root circles in a pot or grows against a hard surface, or when a tree has been planted too deep. In a lawn they can also be pushed in by buried obstacles.
Why it matters here
Many Northern Nevada street and yard trees were planted in rows when subdivisions were built and have been growing against curbs, walks and foundations ever since. A root that grows into a pavement edge may turn, and a maple, honeylocust or ash that looks fine in summer can decline slowly from the base. See silver maple and honeylocust.
A girdling root is also a stability issue. The roots that matter most for holding a tree up sit close to the trunk, in the structural root zone. Take away or compromise one and the tree's grip changes.
What an arborist does about it
The arborist exposes the base, looks at how many roots are involved and how much of the trunk is constricted, and decides whether pruning the offending root is safe for the tree. Taking out a large root is a judgement call, because it can cost the tree anchorage. Where the damage is advanced or the tree stands over a target, removal can be the honest answer. The assessment is part of a free estimate.
Sources
- International Society of Arboriculture, Trees Are Good: New Tree Planting (brochure) (read October 17, 2026)