How stump grinding works, from the first pass to the pile of chips

What is stump grinding?

Stump grinding is the process of cutting a tree stump into small wood chips with a machine, working from the upper surface of the stump down to below the soil line. The roots below that depth stay in the ground. Iowa State Extension calls grinding the quickest, easiest and safest way to remove a stump, and says the drawback is cost.

The stump grinder does the work, and an operator steers it. This guide explains each step in plain terms, so you know what you will see on the day and what to ask before it. For how grinding compares with pulling or digging out a stump, read stump grinding vs stump removal.

What does a stump grinder look like and how does it cut?

A stump grinder is a small engine-driven machine with a large steel wheel on an arm. EquipmentShare, an equipment rental company, says these machines typically use a high-speed disk with teeth to grind the stump into small wood chips. The disk is the cutter wheel. The replaceable carbide teeth bolted around its edge do the cutting.

The operator does not push the wheel straight down like a drill. They swing it across the stump in sweeps and lower it a little each time. Each sweep shaves off a layer of wood. EquipmentShare also lists emergency shut-off switches and protective shields to stop debris from flying as common safety features.

Machine size varies. Smaller handlebar models suit small stumps. Larger tracked or wheeled machines suit bigger stumps. EquipmentShare says smaller models fit occasional use, while larger models suit professional work on multiple or larger stumps.

What are the steps of a stump grinding job?

A typical job follows the same order each time. The steps below combine the equipment company’s description with the extension advice on depth and cleanup.

Step 5 is where you have a say. Tell the crew whether the stump only needs to be below the mower blade or deep enough to plant over.

How deep does the grinder go?

Iowa State Extension says grinders typically take the stump and any large lateral roots down 8 to 12 inches. The University of Illinois Extension gives a wider range: flush with the soil line to over a foot deep. EquipmentShare gives 6 to 8 inches below ground level as a stopping point in its how-to steps.

These numbers come from different sources and describe different machines, so treat them as a range and not a promise. Depth often changes the price. The University of Illinois Extension says that often, the deeper you want a stump ground out, the more it will cost you. Read more in how deep stump grinding goes. Terms like grinding depth and below grade mean the same measurement: how far under the soil surface the wood is removed.

How long does it take?

Iowa State Extension says the stump is gone within a matter of hours. EquipmentShare gives a wider range of 15 minutes to several hours, depending on stump size and wood hardness. A wide, hard stump takes longer than a narrow, soft one.

The grinding itself is only part of the visit. The crew also moves the machine in, clears the area and cleans up. Hard-to-reach stumps add time. For a closer look, see how long stump grinding takes. Nothing here sets a time for any single company. Ask for a time window when you request your quote.

What is left behind afterward?

A pile of stump grindings fills the spot where the stump stood. These are the wood chips the grinder makes. Iowa State Extension says most arborists will not remove this material unless it is requested, and that the hole is only filled if requested. It adds that both services typically have an additional cost.

Leftover chips matter if you plan to grow grass. The University of Illinois Extension says to haul off the chipped stump debris and fill the hole with quality topsoil before planting turfgrass. Its reason is that wood mixed into soil can tie up nitrogen as it breaks down, which makes it hard to grow a lawn or another plant. Iowa State Extension says the same kind of shavings will drastically change the soil’s structure, moisture-holding capacity and nutrient balance.

The soil may also sink later. Purdue Extension says it can take several years to fully decompose the stump unless it was ground very deeply or removed with an excavation machine. Plan to add soil. The guide to what comes after stump grinding covers the steps.

What stays in the ground

Grinding removes wood from the stump and the large roots near it. Roots farther out stay and break down slowly. Some stumps also resprout after a tree is cut, according to Iowa State Extension. See do roots die after stump grinding for what the sources say.

What can go wrong: rocks, metal and utility lines?

The main risks are hidden objects and buried lines. EquipmentShare says to clear rocks, debris and other objects that could damage the grinder before starting. A nail, wire or stone buried in a stump can chip teeth or throw debris. This is why guards and shields exist.

Buried lines are the other risk. Some lines are public, such as gas or electric service. Others belong to the owner. OHIO811 defines private utility lines as lines owned by the property owner that often run from the house to individual systems and structures on the property. Its examples include down spout drain lines, electric lines to a shed or lamp post, and septic lines.

What do OHIO811 and Kentucky 811 say?

Do not assume the law requires an 811 call for stump grinding. The pages below do not name stump grinding, so read them yourself and ask your company how it handles marking.

Markings cover public utilities that belong to OHIO811 or Kentucky 811 members. OHIO811 says not all utilities are registered and that private lines may need to be marked by you or your excavator using a utility locating service for hire. See before you grind: 811, tree lawns and permits and what to mark yourself.

How does grinding compare with other ways to remove a stump?

Grinding is the fastest of the options Iowa State Extension describes, and it costs more than the slow ones. The extension page lists grinding, natural decay and digging, among others. The table below sets them side by side using that page.

Burning is on the same page’s list of methods to avoid. Read stump grinding vs stump removal for a full comparison and do it yourself or hire a pro for the owner’s side.

Why does the type of machine matter on a lawn?

Weight and tires or tracks decide how much a machine presses on turf. Vermeer, a stump cutter maker, says tracks spread ground pressure for soft terrain and wheels offer transport speed. A tracked vs wheeled stump grinder choice is therefore about ground, not about cutting power.

Vermeer also says both its track and wheel models fit through 36-inch gates. Measure your gate and tell the company about narrow paths, steps or slopes. The post on what a turf-friendly stump grinder is explains the term in more detail.

Cincinnati Stump Grinding states on its Angi profile: “Our powerful, turf-friendly machine will reduce your tree stump to wood chips quickly.” That is the business’s own wording. This guide does not name a model or brand for it.

How do you compare quotes for grinding?

Compare what each quote includes and not only the total. Iowa State Extension says arborists will charge by the size of the stump, measuring it at its widest point. Ask whether the price covers chip removal, hole fill and cleanup, since sources say these often cost extra. The guide on how to choose a stump grinding company lists questions to ask.

Next step

Read how deep stump grinding goes to decide what depth you need. Call (513) 587-6772 or send photos for a free estimate.