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Cutting roots

cutting rootsCutting roots for any reason under existing trees can severely damage the tree (see right photo). Many roots are located just below the surface of the soil. Adjust the location of the utility lines, driveways, buildings, and planting holes to avoid cutting roots under the canopy. Even cutting small (less than one-half inch) roots under or outside the edge of the canopy for long stretches can cut off water supply to the tree. This can cause the tree to decline or die during the next several years.

The rare spruce pine tree shown at right was cut on two sides of the trunk about ten feet from the trunk. Older trees treated like this can decline and die over a 10 to 15 year period. Make root pruning cuts only with sharp pruning tools, not tractors and trenching devices. Cutting roots close to the trunk as shown below right can cause tree failure a decade or more later. The roots of this tree were cut to construct a driveway about 15 years ago.

Driving vehicles under the canopy compacts soil. Even lawn mowers can compact soil. Severely compacted soil can cause severe tree health issues. Vehicles also damage and break surface roots as they turn on the soil. If mature tree health is important to you, do not allow ANY vehicles to operate underneath trees. If there appears to be no option, then consider the preventive solutions listed below.

Preventive solutions

  • Hire a consulting arborist.fallen tree
  • Construct a fence at the edge of the tree canopy to prevent ALL vehicles from operating there; establish fines for violations.
  • A 12-inch thick layer of coarse bark mulch can be spread under the canopy and mulch can be covered with steel plates. Vehicles drive on the plates. This system has been successfully used on many sites to preserve mature trees.
  • Do not use the area under the canopy as a parking zone or materials storage area.
  • Restrict ALL vehicles to fenced-off transportation corridors and materials storage areas.
  • Tunnel under the roots using a trenchless technology device which installs utilities without cutting a trench.