What makes it safe or unsafe
Distance from the trunk is the main variable: the closer to the trunk, the bigger the roots and the greater the harm. Roots near the base belong to the structural root zone, and cutting them risks the tree's stability. Farther out the roots are smaller, and a tree can regrow them. How much total root can be taken depends on species, age, vigour and soil.
Clean cuts matter. A root torn by a backhoe leaves a ragged end that decays, while one cut by hand or exposed with air and then cut clean seals better. Roots are cut once, ahead of the work, not repeatedly.
Why it matters in Northern Nevada
Trees here live on small water budgets, so they have less to spare when roots go. A cottonwood with roots cut for a new fence may show nothing for a season and then lose limbs. On old lots, root conflicts with walks, driveways, sewer lines and foundations are common. Root barriers are a way to steer future growth, and our guide on root barriers and when they work is plain about their limits.
Always call 811 first. Roots are not the only thing in the ground.
What an arborist does about it
The arborist decides whether root pruning is safe, where to cut, how far from the trunk and in what stages. Sometimes the answer is no: if a project needs roots that the tree cannot spare, the plan changes or the tree comes out. Work is timed with the tree's condition in mind. Large cuts near the trunk are avoided.
Sources
- International Society of Arboriculture, Trees Are Good: Avoiding Tree Damage During Construction (brochure) (read October 17, 2026)
- Call 811: Know what's below (read October 1, 2026)