Why grind a stump?
After a tree comes down, the stump remains. Stumps are tripping hazards, get in the way of mowing and landscaping, can sprout new shoots, and can attract wood-boring insects and fungi as they rot. Grinding removes the visible stump and the top layer of roots so the area can be replanted, paved or turned back into lawn.
Grinding versus full removal
- Stump grinding uses a machine with a spinning cutting wheel to chew the stump into chips, usually several inches below the soil surface. The deeper roots stay in the ground and decay over time. Grinding is the most common choice because it's faster, less disruptive and less expensive.
- Full stump removal pulls out the stump and much of the root ball with heavy equipment. It's sometimes needed before building a foundation, patio or pool in the same spot, but it leaves a large hole and disturbs more of the yard.
How deep should grinding go?
The depth depends on what you plan to do with the area. Grinding a few inches below grade is usually enough for lawn. For replanting a tree or shrub in the same spot, deeper grinding and removing chips helps. For hardscape such as pavers, concrete or a shed, tell the contractor in advance so they can grind deeper and remove more root material. Ask the contractor to state the depth in the quote.
Surface roots
Large surface roots radiating from the stump can also be ground. Tell the contractor whether you want them removed, since it adds time and cost.
The chips
Grinding produces a large pile of wood chips mixed with soil. Some homeowners use them as mulch elsewhere in the yard; others want them hauled away and replaced with topsoil. Fresh chips from stumps can temporarily tie up nitrogen in soil if mixed into planting beds, so many people prefer to remove them from the hole and fill with topsoil before seeding or planting.
Utilities and buried lines
Before grinding, buried utilities must be located. Grinding equipment can cut gas, water, electrical, irrigation and communication lines. In the United States, calling 811 before you dig arranges for utility companies to mark their buried lines. Private lines, such as irrigation, landscape lighting and lines to a detached building, aren't marked by 811; point them out to the contractor.
Access
Stump grinders range from small machines that fit through garden gates to large ones that need wide access. Measure the narrowest gate or path to the stump and tell the contractor, so they bring the right machine. Grinding on slopes or near structures may require extra care.
Questions to ask
- How deep will you grind, and will you grind surface roots?
- What happens to the chips?
- Will you call in a utility locate, and how will you avoid private lines?
- Can your equipment fit through my access?
- What's the price per stump, and is cleanup included?
After grinding
The ground over a ground stump may settle as buried roots and chips decay, so expect to add soil over time. If you're reseeding lawn, rake out most chips, fill with topsoil, firm it and water well. If sprouts appear from remaining roots, cut them back promptly; most stop after a season or two.