Tree root grinding is a mechanical process that uses a specialized machine to shred the remaining root mass of a tree after the trunk has been cut down. This method effectively removes the visible and near-surface wood, turning it into small chips and sawdust. Grinding is necessary for clearing the space for new landscaping or construction projects, as a large root mass prevents mowing, planting, or building.
The process also removes potential hazards, since exposed roots can be tripping risks. Furthermore, grinding eliminates the tree’s ability to sprout new growth, which often occurs when a tree is simply cut at ground level. Removing the decaying wood also reduces the risk of insect infestation, as pests like termites and carpenter ants are attracted to the material.
Essential Preparations Before Grinding
Thorough preparation of the site and the operator is required before grinding. The most important initial step is to contact the national call-before-you-dig number, 811, or your local utility location service to have all buried lines marked. This prevents damage to gas, electric, water, or communication lines that may run near the root system.
The operator must wear appropriate personal protective equipment (PPE), including safety goggles or a face shield to guard against flying wood chips, and hearing protection due to the high decibel levels of the machine. Heavy-duty gloves and safety boots are also recommended. All clothing should be fitted, avoiding loose items that could catch in the machinery.
Selecting the right equipment depends on the size of the root mass; smaller, push-style handlebar grinders are suitable for shallower roots, while larger units are better for extensive or deep systems. Once the grinder is on site, the area immediately surrounding the root mass must be cleared of debris. Rocks, stones, metal, or other hard objects can damage the carbide teeth on the cutter wheel, leading to costly repairs and an inefficient grind.
Any tall portion of the root mass should be cut down as close to the ground as safely possible with a chainsaw, as this significantly reduces the work the grinder needs to perform. Surface roots extending out from the main mass should be exposed by clearing away surrounding soil, allowing the grinding wheel to address them methodically.
Operating the Grinder: The Step-by-Step Process
The grinding process begins by positioning the machine so the cutter wheel is just above the edge of the root mass. For safety and stability, the machine’s wheel brakes or lock mechanisms should be engaged before operation. With the engine running at full throttle, the cutting wheel is engaged, and the blade is slowly lowered to begin the initial pass.
The technique involves a systematic side-to-side sweeping motion across the root mass, controlled by hydraulic levers or handlebars. The operator should avoid forcing the cutting wheel into the wood, instead allowing the rotating teeth to gently shave away the material in thin layers with each pass. This gradual feeding prevents the engine from stalling or “bogging down,” which can damage the machine.
After each complete sweep across the width of the root mass, the operator lowers the cutting wheel slightly deeper, repeating the sweeping action. This continuous process slowly reduces the height of the mass, moving from the top down and across the entire width. Once the visible root mass is gone, grinding continues to the required depth below grade, typically six to twelve inches, depending on whether the area will be re-seeded or replanted.
Tackling wide or stubborn sections requires patience and a gradual approach. When encountering a large, dense section, focus on the perimeter first, slowly reducing the diameter before working toward the center. Monitor the machine constantly for signs of strain, adjusting the speed of the sweep and the depth of the cut to maintain optimal grinding efficiency.
Cleanup, Disposal, and Restoring the Landscape
Once grinding is complete, the immediate task is to manage the substantial volume of wood chips and organic debris that remains. These grindings must be raked away from the cavity to fully expose the hole and assess the final depth. Removing this excess debris is important because allowing a deep layer of fresh wood chips to decompose can temporarily deplete the soil of nitrogen, which is necessary for new plant growth.
The resulting wood chips can be repurposed as mulch in other areas of the yard, or they can be hauled away entirely if a clean planting surface is desired. The cavity created by the grinding process must then be filled to level the ground and prevent future sinkage. Topsoil is the preferred material for filling, though a mixture of topsoil and finer wood chips can also be used.
The soil should be packed gently as it is added to the hole. A slight mound above the surrounding grade is often recommended to account for natural settling as any remaining small root fragments decay. Once the area is level, the surface is ready for restoration, which might involve overseeding, laying down sod, or planting new shrubs or flowers.