At Texas Tree Surgeons, we love trees and we love our customers, and we have created a series of articles covering tree basics. If you have a specific tree question, let us know!

When providing a proposal for a tree removal, our arborists also evaluate the site for stump grinding. While having the stump ground is not always necessary, many people prefer to deal with the stump at the same time as having the tree removed. Stump grinding allows the property owner to use the area where the tree once stood for laying sod or planting a flower bed. The stump grinder also produces mulch that has many uses around the yard. Here are answers to some common questions we get about stump grinding.

Non-natural material, such as this lighting cable, may reduce grinding depth.

How deep CAN THE stump grinder go?

We generally grind four to six inches below grade (ground level). If deeper grinding is needed, it can be requested, although the price of stump grinding may increase. The depth to which a stump can be ground is subject to some limitations, however.

• The stump-grinding blade has a diameter of about 10 inches, and can only be maneuvered up and down within a specific range.
• A tree that grew in shallow soil, such as over the limestone bedrock prevalent in the Dallas area, may not have six inches of grindable depth.
• Other material near or around the tree may limit how deep the grinder can go. While the stump grinder is powerful, it is only designed to handle plant material, wood, and dirt. Take note of:
  • Fencing, concrete, brick, or rock around a stump (such as a tree ring)
  • Nearby trees that may have roots under the tree stump
  • Swimming pools, walkways, and patios that may prevent the grinder from reaching all of the root material
  • Lawn irrigation, sprinkler systems, tree lighting wiring, and buried hoses
• We generally do not grind deep enough to risk interfering with properly-installed utility lines or buried cables, but unforeseen obstacles can be encountered that necessitate a shallower grind.

What exactly lies beneath the roots of a tree or the surrounding soil may be a mystery, even to the homeowner. While we are very careful when grinding a stump, we will not take responsible for damage to irrigation lines or other items located below ground that we are not aware of. It is important to inform your arborist of any sprinkler systems or other objects that might be in the area to be ground before the work begins.

Grinder blade in action; grind depth can be limited by blade size.

What is left after a stump is ground?

As the blade grinds the stump and surface roots, it produces a mulch made up of tree material and dirt. The mulch produced by stump grinding can take up a much greater volume than the original stump. (It can be helpful to think of the difference between a block of cheese and that same cheese after it is grated.)

Mulch from stump grinding is valuable organic material that decomposes more quickly than many other kinds of mulch, as there are generally smaller wood particles present, and more soil to help it break down. It is our standard practice to push the mulch back into the area that has been ground (“backfilling”). Even so, there is usually a large pile of mulch left above ground, often much more than the tree owner expected. Because of its composition, the mulch does settle fairly quickly, but many people prefer to use the mulch around their yards, rather than leaving it where the stump once was.

Stump grinder mulch can be used for composting or applied in flower beds. (Depending on exact composition of the mulch, it may not perform in the same way as typical hardwood mulch, and may need to be replaced sooner.) After some time, when the mulch has settled, it can be packed into the ground-out area, making the area ready to be prepped for laying sod or for planting a flower bed or other small plants. If requested, we can provide mulch bagging and/or bagged mulch haul-off as an additional service after stump grinding, but our standard practice is to leave all grinder mulch on-site.

A stump of about 50 inches before grinding…

…the mulch from the same stump after grinding. The mulch left after after a stump is ground makes a great addition to flower beds and compost piles.

Will the tree come back after A stump is ground?

Even with stump grinding, some species of tree can still send up shoots and new growth from the roots left below ground. Crape myrtles, chinaberry trees, hackberries, and Bradford pears are some common species in the area that can be very persistent in growing back. The sprouts that return after stump grinding can be trimmed or mown down and will eventually stop coming back, as the remaining roots use up their energy reserves. Commercially-available woody stem killer can be used to accelerate the dieback of the roots. White vinegar can also be used as an organic alternative to commercial root killer.

Can I replant after a stump is ground?

We are often contacted about removing a tree that the owner would like to replace. We do not recommend trying to re-plant trees in the same area where a tree was removed and the stump ground. Even with a deep grind, an extensive root system remains underground. The old root system can interfere with the new tree’s attempts to become established. Furthermore, if the old tree had a disease, that disease may still be present in the remaining root tissue, and can be transmitted to the new tree. When replanting is desired, we can discuss finding a location that is far enough from the removed tree to lessen the likelihood of interference from the old root system. If homeowners’ association or municipal restrictions require a tree to be replaced in a certain location, excavation or hand digging may be the only options.

When a tree falls, the root and stump area can be difficult to grind.

Can every stump be ground?

In the case of a tree becoming uprooted (because of storm damage or root rot, for example), the stump cannot be dealt with as easily. If there is a large amount of root material above ground, the stump grinder may be physically unable to reach it. Depending on the type of tree and how it grew, it may pull up a great deal of dirt, turf grass, and other underground material when it falls. What is left after grinding an uprooted stump may be more dirt than tree matter, and may not be suitable for use as mulch.

Weather is also a factor that can determine how and when stump grinding can be performed. A long period of rain can cause the soil to become waterlogged. Operating a stump grinder in heavy, wet soil can not only make a bigger mess than usual, but can damage the surrounding area due to the weight of the machine. It may be necessary to wait until the area dries out before attempting even a “standard” stump grind.

If a customer has a special circumstance, like an uprooted tree, or there are multiple stumps in one area to be ground, we always send an arborist to assess the situation before providing a quote or scheduling the stump grinder.

How much does stump grinding cost?

The cost of stump grinding is dependent upon three main factors: the size of the stump, the location of the stump, and how deep the grinder needs to go. While we generally provide a stump grinding price when we give a quote for tree removal, we are also happy to evaluate any other stumps you may want to have ground.

How DO I MEASURE A STUMP?

The base cost for stump grinding is determined by the diameter of the stump in inches, including any above-ground roots. This measurement can be taken before or after a tree is removed. To get the right measurement, it is important to go “from dirt to dirt.” This means measuring from the stump edge or root point (where it touches the dirt) farthest from the trunk to the opposite edge or root point. It is also important to measure from different directions and to take an average measurement, as this most accurately reflects the area to be ground. The “dirt-to-dirt” measurement can be quite a bit larger than the diameter of the tree trunk, and we do see situations where the stump grinding is more costly than removing the above-ground tree.

Surface roots need to be included in the stump measurement.

This is a 75-inch stump, measured “dirt to dirt” at the yellow line. Measuring on the trunk is inaccurate: if this tree were measured at the red line, the result would only be 37 inches, which is not the actual area to be ground.

Even after a tree is cut down, properly measuring a stump can be tricky when there is a root flare and surrounding vegetation.

Can the stump grinder reach my stump?

Our standard stump grinder is a machine that is seven feet long and three feet wide. At the front is a rounded blade (similar to the tip of a chainsaw) that chips away wood as it moves across the stump. The stump grinder is designed to fit through standard gates, but some older or narrow gates may not be able to accommodate it. The weight of the machine may also prevent it from reaching certain areas without damaging walkways or ground cover. While the grinding blade has some maneuverability, clearance of at least seven feet on one side of the stump is required to allow the grinder to access the area to be ground. In smaller areas with less clearance, it is possible to use our smaller stump grinder, but this can increase the time and cost of the procedure.

Stump grinder blade

Can i just leave the stump?

Iit is not necessary to grind or otherwise remove a stump after a tree is taken down. We have customers who request a tree not be cut all the way to ground level, and use the remaining stump as a plant stand, table base, or just a yard feature. Even if the stump is cut close to the ground, it can last several years. Preservative coatings can also be applied to prolong the life of a standing stump.

Some homeowners prefer to let a stump decompose naturally over time. Old stumps can become habitats for fungi, insects, and other creatures. As the stump breaks down, it can become rich organic material that can be added to compost or used in planting. If a stump is left unground, however, it can continue to send out new growth for years after the tree has been removed. Drilling holes in the stump and filling with Epsom salt or using commercial stump killer can accelerate stump dieback, but those chemicals can be toxic to surrounding plant life. Treating the stump with chemicals can also make the area hazardous to people and pets.

A stump left to decay naturally. The tree was removed approximately 5 years ago. (Photo courtesy Tom Davis)

More Questions about stumps? Let us know!

At Texas Tree Surgeons, we love trees and we love our customers, and we believe that the more people learn about their trees, the better we can serve our community. We hope this article has helped answer your questions about stump grinding and what your options might be. If you have any specific questions, let us know, and we’ll be happy to send an arborist out to evaluate your needs and offer our suggestions and expertise.