What Is Grubbing? Clearing, Grubbing and Forestry Mulching, Explained Side by Side
The Gibson Environmental Services crew
More than 10 years clearing land, cutting trails, and running forestry equipment in Southeast Michigan.
Grubbing is the part of land clearing that happens below the ground: pulling the stumps, the roots and the buried logs out of the soil so the site can be graded, compacted and built on. Clearing is the part above the ground, cutting and removing the trees, brush and debris. Forestry mulching is a third thing, a clearing method that grinds the trees, brush and stumps down to the ground in one pass and leaves the roots and a chip layer behind, so nothing is dug and nothing is hauled.
Which one a project needs depends on what the ground is for. A driveway, a building pad, a septic field or a road needs grubbing under its footprint. A pasture, a food plot, a trail, a thinned woodlot or a lot that will stay as ground needs clearing and usually does best mulched. This guide lays the three side by side, explains what each leaves behind, and covers how the work is measured, because the phrase 'clearing and grubbing' on a bid means something specific.
The Three Terms, Defined the Way Specifications Define Them
Public works specifications are where the words get their exact meaning. A state highway specification describes clearing as cutting and disposing of the trees, brush, windfalls, logs and other vegetation inside the clearing limits, and grubbing as removing the roots, stumps and other timber inside the grubbing limits. The federal conservation practice standard for land clearing defines the practice as the removal of trees, stumps and other vegetation from wooded areas. City specifications draw the line at the surface and add the depth: stumps and roots removed to at least twelve inches below the subgrade or the original ground, whichever is lower, inside the construction area, and stumps simply cut flush with final grade outside it.
| Term | What it means | What it leaves | Typical equipment |
|---|---|---|---|
| Clearing | Cutting and removing everything on or above the ground surface: trees, brush, downed wood, debris | Stumps at or near grade, roots in the ground, material piled, hauled, chipped or mulched | Forestry mulcher, brush hog, saws, grapple |
| Grubbing | Removing stumps, roots and buried wood from below the surface, usually to a specified depth | Disturbed soil, a spoil pile of stumps and roots to dispose of, a site ready to strip and grade | Excavator with a thumb or root rake, dozer with a rake, stump grinder for single stumps |
| Stripping | Removing the topsoil and organic layer after grubbing so fill sits on firm subgrade | Stockpiled topsoil, exposed subgrade | Dozer, scraper, excavator |
| Forestry mulching | Grinding trees, brush and stumps down to the ground in place and spreading the chips | A chip layer over the whole area, roots below grade, no piles, no spoil | Tracked skid steer with a forestry mulcher |
Close-cut clearing, a term some specifications use, sits between clearing and grubbing: everything cut at or near existing grade, roots left. That is, in practice, what a forestry mulching pass delivers.
When a Site Needs Grubbing
Grubbing is for ground that will carry a load or be shaped. Roots and stumps left under fill rot, the fill settles, and whatever sits on it cracks. So the footprint of anything built gets grubbed:
- House and garage pads, pole barns, foundations and slabs.
- Driveways, roads, parking areas and culvert crossings.
- Septic drain fields and the area around a well.
- Ponds, basins and anything that will be excavated or shaped.
- Fill areas and any ground that will be compacted.
Everything outside those footprints is a different question. The lawn beside the pad, the woodlot behind the house, the field in front: none of it carries a load, and all of it does better with its roots in place holding the soil. On a new home site we mulch the whole lot to open it up and make it walkable, the surveyor stakes the footprint, and the excavation crew grubs only the ground that needs it. Our guide to clearing a lot for a new house in Michigan walks through that sequence.
When Mulching Is the Better Answer
Pasture, hay ground and food plots
Seed takes through the chip layer, the roots feed the soil as they rot, and there is no spoil to deal with. See pasture reclamation and food plot site prep.
Trails, lanes, shooting lanes and fence rows
A corridor opened by a mulcher is drivable the same day and the chips keep it from washing. Grubbing a trail would leave a ditch.
Woodlot thinning and invasive brush
The keeper trees stay, the understory goes, and the ground between them is not torn up. See invasive growth removal.
Overgrown lots that will stay as ground
A lot you want to see, mow and use again, without building on it yet. The mulched surface mows like a field by the second summer.
Wet ground, slopes and lakefront
No bare, disturbed soil to erode into the water or down the hill. See lakefront clearing.
Ground that will be built on later
Mulch now to open the site and plan it; grub the footprint when the build is scheduled. The two jobs are a year or more apart on many lots.
Our side-by-side guide to forestry mulching vs excavator land clearing covers the machines, the mess and the ground each one leaves. The short version: the excavator is the right tool for the footprint and the wrong tool for the rest of the lot.
What Grubbing Does to a Site
Pulling a stump pulls a root ball, and a root ball is a hole. Grubbing an acre of mature woods leaves hundreds of holes, a pile of stumps and roots that is mostly air and dirt, and bare soil that erodes with the first rain. That is why grubbed ground is stripped, graded and stabilized right away, and why the spoil pile is one of the bigger costs of the job: stumps are awkward to haul, slow to burn and take a decade or more to rot in a pile. On a mulched site none of that exists, which is the trade for leaving the roots.
How Clearing and Grubbing Are Measured
Estimators measure clearing by area and grubbing by what is in the ground. A clearing bid counts acres or square feet and grades the growth (light brush, saplings, mixed woods, mature timber), because the same acre takes an hour of mowing or a day of mulching depending on what is on it. A grubbing bid adds a stump count, usually by diameter class, and a depth, because every stump is a dig, a lift and a haul. Access, slope, wet ground and the distance to a disposal site move both numbers. On our own jobs we price after a walk-through, by the project rather than by a rate card, and our guide to how forestry mulching is priced explains what we look at.
On time: a forestry mulcher moves through light brush and saplings at about an acre a day and slower in heavy saplings and small trees, so twenty acres of overgrown field is a job measured in weeks. Grubbing the same twenty acres is a different scale of work, measured in machine-days per acre plus the hauling, which is why it is reserved for the footprint.
The Order of Work on a Site That Needs Both
- Walk and mark: keeper trees flagged, the build footprint staked, access and staging decided.
- Clear: forestry mulching across the lot, which opens the site, makes it walkable and leaves the ground covered. See site preparation.
- Grub: the excavator pulls stumps and roots inside the footprint to the specified depth and hauls or piles the spoil.
- Strip and grade: topsoil stockpiled, subgrade shaped and compacted.
- Stabilize: seed and mulch, or the chip layer already there, on everything outside the pad.
Doing the clearing first, with the mulcher, means the excavator starts on a clean, visible site and digs only where it has to. It also means the rest of the lot is finished the day the mulcher leaves, not the day the build ends.
Common Questions
What is the difference between clearing and grubbing?
Clearing removes what is on or above the ground: trees, brush, downed wood and debris. Grubbing removes what is below it: stumps, roots and buried wood, dug out to a specified depth so the ground can be graded and built on.
What is grubbing in land clearing?
Grubbing is the digging-out step. After the trees and brush are cut, an excavator or a dozer with a root rake pulls the stumps and major roots out of the soil, usually to about twelve inches below the finished subgrade inside the construction area, and the spoil is hauled or piled.
What is grubbing in construction?
The same thing, on a building site: stumps and roots removed from under the footprint of the pad, the drive, the drain field and any fill, so nothing rots and settles under the structure. Specifications list it with clearing as the first item of site work.
What equipment is used for clearing and grubbing?
Clearing: a forestry mulcher on a tracked skid steer, a brush hog for fields, saws and a grapple for hand work. Grubbing: an excavator with a thumb or a root rake, a dozer with a rake, and a stump grinder for single stumps in a lawn.
Does forestry mulching include grubbing?
No. The mulcher grinds the trees, brush and stumps down to the ground and leaves the roots below grade under a chip layer. That is close-cut clearing. Where a pad or a drive is planned, the roots under that footprint are grubbed afterward by an excavator.
How long does it take to clear 20 acres of land?
It depends on what is growing and whether the stumps come out. A forestry mulcher moves through light brush and saplings at about an acre a day, so twenty acres of overgrown field is a job of a few weeks. Grubbing the same ground is measured in machine-days per acre plus the hauling, which is why it is reserved for the building footprint.
How is clearing and grubbing computed on a bid?
Clearing by area, graded by the density and size of the growth. Grubbing by stump count and size, and by depth. Access, slope, wet ground and haul distance move both. We price by the project after a walk-through rather than from a rate card.
Sources and Further Reading
The definitions and the twelve-inch depth above are from the public specifications below; the mastication note is from Oregon State University forestry extension.
USDA Natural Resources Conservation Service: Conservation Practice Standard 460: Land Clearing
Wisconsin Department of Transportation: Standard Specifications, Section 201: Clearing and Grubbing
City of Liberty, Missouri: Standard Specifications, Section 1000: Clearing and Grubbing
Oregon State University Extension: Other options for treating slash after a timber harvest (mastication)
Iowa State University Extension and Outreach: How to Remove Tree Stumps
Where We Do This Work
The work in this guide is done across eight Southeast Michigan counties from our base in Royal Oak. Every county page lists the townships we work in most, with a page for each.
Not Sure Whether Your Site Needs Grubbing?
Walk it with us. We will tell you which ground mulches, which ground gets dug, and in what order, before anything is cut.