How to grind a stump and what the grinder does
A stump grinder is a machine with a spinning cutting wheel. Hydraulic cylinders move the wheel side to side and up and down, so it chips the wood away a layer at a time. Some grinders are built only for stumps, and others mount on tractors, skid steers or excavators.
A grinder cuts below the ground, so buried lines matter. Texas law requires homeowners, excavators and contractors to call 811 at least two days before digging, and the call is free. Make that call before a stump is ground, and mark any sprinkler lines you know about.
How deep a stump gets ground
How deep a stump gets ground depends on what goes in the spot next. Grass needs less depth than a flower bed, a path or edging. Illinois Extension describes grinding depths from flush with the soil to more than a foot deep, and it notes that deeper grinding generally costs more.
Deep grinding can leave a large hole, so plan on soil to fill it if you want grass there. Agree on the depth before the grinder arrives, and get it in writing.
What happens to the roots after grinding
Grinding takes out the stump and any surface roots you list. The side roots stay in the ground and rot slowly. Illinois Extension notes that a cut tree often sprouts again from the stump or from the roots around it.
Hackberry, elm and some oaks may send up shoots from roots left in the ground. Grinding below the lawn stops most shoots. Mow or clip any new sprouts during the first season, and they stop once the roots use up their stored energy.
To stop sprouts before you grind, Illinois Extension suggests treating the outer ring of wood on a fresh cut with a herbicide that contains glyphosate or triclopyr. Read the label and follow it exactly.
What to do with the wood chips and the hole
As the wheel chews up the stump, the chips mix into the soil around it. Wood chips mixed into soil tie up nitrogen as they break down, which can make it hard to grow grass right where the stump stood. Illinois Extension suggests hauling off the chips and filling the hole with good topsoil before you plant grass there.
The ground also sinks as old roots and chips rot. Add soil as the spot settles, then seed or lay sod.
Planting a new tree near an old stump
Illinois Extension advises against planting a new tree on top of a recently ground stump. Its forestry specialist suggests planting at least three feet away, in fresh soil with room for new roots.
When to grind a stump
Grind a stump when you want to mow, plant or build over the spot this year, and match the other options to what you want there next.
- Grind it when you want to mow, plant or build over the spot this year.
- Let it rot when it sits in a back corner and you can wait a few years.
- Have it dug out when a builder needs the main roots gone for a pool or a slab.
- Leave it when it does not bother you, and use it for a planter or a seat.
There is rarely a rush with an old stump, so take the time to pick the option that fits.
Renting a stump grinder or hiring a crew
Illinois Extension says digging a stump out by hand gets hard fast, and its author would not hand-dig a trunk much over six inches across. It also warns that pulling a stump out with a vehicle often ends in costly auto repairs.
If the tree is still standing, book tree removal service and the grind together, so one estimate covers the tree, the stump and the chips. Our guide to tree removal cost explains what changes the price.
If a whole corner has gone wild with brush and old stumps, start with tree and brush removal, then grind the stumps that are left.