Equipment options: Stump cutters and grinders

When removing a tree or large shrub, many contractors leave the stump behind. However, you have some important issues to take into account when dealing with stumps. For example, invasive roots can damage foundations and septic systems, and you face trip hazards on sidewalks, curbs and turf areas. When ignored, these issues can lead to unnecessary and costly litigation.

Therefore, it is important for you to assess the situation when it comes to a stump. You need to determine if it needs to be removed. If so, will removing it require chemical treatment or grinding?

Chemical treatments In areas such as slopes, planting beds with groundcover or areas generally inaccessible to pedestrians, you may be tempted to simply cut a stump flush to the ground and leave it at that. However, some vigorous trees-such as willow or eucalyptus-tend to sprout back from flush cuts, and their invasive roots continue to grow.

In these situations, you need to use glyphosate (Monsanto's Roundup Pro or Rodeo) or phenoxy chemicals (PBI/Gordon's Brushmaster is labeled for this use) to eliminate resprouting and deter further root growth. Particularly in warm climates, you can perform cut-stump treatments most times of the year and they'll still be effective. However, glyphosate's labeling recommends application during the growing season for best results. A few other products, though not typically marketed to the landscape industry, have labeling for cut stumps. These include several Dow AgroSciences products containing the active ingredients triclopyr or picloram.

If you've decided to use chemicals, have the herbicide ready to apply just after you make the final base cut so that you can immediately treat the stump. If you wait to apply the chemical (even as little as one-half hour after cutting), it will be less effective because the stump will not completely absorb the herbicide. If this happens, you may need to make a second application. Some labels suggest adding oil to the herbicide for increased effectiveness.

When you apply the chemical, you don't need to coat the entire stump. You only need to treat the cambium layer. This is the ring of wood inside the inner bark. Thus, after cutting, spread the chemical (using a brush) in an "O" pattern on the cut surface of the stump, around the cambium layer. As always, read the entire label before using any chemical product and use them only according to label instructions. Cut-stump treatment usually requires higher concentrations of the product-the label will indicate what concentration to use.

Don't be discouraged if you find the stump resprouting after you've applied a herbicide. Some vigorous species may need a second application. Do not apply herbicide to stumps located near desirable trees. Because root systems often graft to one another, the herbicide can travel from the treated stump to other trees that you don't want to harm. When this happens, those trees can experience symptoms of dieback and defoliation.

The daily grind When a stump is a liability hazard or just an aesthetic nuisance, it is a candidate for removal. If this is the case with a stump on one of your sites, it is important that you carefully plan the removal process. Recent technology in stump-grinding equipment has made the removal process efficient and cost-effective for any size of stump. To know what type of grinder is best for your situation, consider the location, stump size and the depth of grinding. Then you can decide whether a hand-held, self-propelled, tow-behind or PTO attachment unit is best for your needs. Here are the general types available:

* Hand-held grinders. If you are working in hard-to-access areas, such as raised planter beds and small back yards, consider a small hand-held grinder. Some have folding handles that allow you to fit them into a truck bed. Advantages of these units are their size and ease of use. Disadvantages, however, include low horsepower and a typically small cutting wheel-often reducing their cutting depth to about 10 inches-which can prevent you from removing the entire below-ground portion of the stump. Even so, if you aren't planning to replant in the same location, then the depth of cut may not be an issue for you.

* Self-propelled grinders. For slightly larger jobs, these self-propelled, hydraulically powered units are designed to fit through a standard yard gate. The depth of cut with these units is about 13 to 15 inches.

* Tow-behind grinders. Your use of these units is limited to areas where you can tow them with a truck. Their advantage is that they have more horsepower and a large-diameter cutting wheel. They can cut to a depth of up to 24 inches. However, these types of machines require more training and experience to operate. For reasons of liability, be sure your crew members are thoroughly trained to operate one of these machines.

* PTO attachments. For large construction jobs where you aren't concerned about damaging turf, these attachments are for use with skid-steer loaders. Most can cut to a depth of at least 24 inches and are hydraulically powered.

Site survey Part of planning ahead for a stump-removal project involves a site survey. For example, you need to call an underground-location service to check for any underground utility lines such as gas, electric, water or sewer. Your local utility company usually provides this service free-of-charge, and you can typically find their toll-free number in your phone-directory's consumer guide. (Irrigation lines are not usually included in these surveys, so you'll need to check with the property owner or irrigation blueprints to know their location.)

Next, be sure to visually assess the area where the grinding will take place. Nearby cars, windows and buildings are susceptible to rocks and debris that the machine's cutting wheel will throw. Plywood sheets and netting around the stump can prevent damage from flying particles.

Performing a complete job Chasing roots is part of the stump-removal process that some contractors often neglect. You should take care to avoid this mistake. Surface roots can run for many feet beyond the root-flare (base) of the stump, and you need to take them into account in the grinding process because searching for them can be time-consuming.

Also, don't forget about cleanup. Chip removal from a ground-out stump can create a pile of chips three to four times the size of the original stump.

If you plan to replant in the same location, don't make the mistake of using the stump grindings as backfill. Decomposing chips tie up nitrogen in the soil. In addition, they often result in mushrooms and soil depressions over time.

A thorough and professional job You assume the liability for risks associated with the grinding process. Be sure that you know all the specifications of the job and have a well-trained crew operating the equipment. The specifications should include cutting depth, extent of root chasing, chip removal and clean-up requirements. Document these in writing for your benefit as well as that of your customer. If you are to provide the backfill, be sure that you've specified the type of soil you will use.

A. Peter Sortwell is vice president/general manager of Arbor Care, a service of Environmental Care Inc. (San Jose, Calif.). He is a certified arborist, past board member of the National Arborist Association (NAA) and past trustee of the National Arbor Foundation. Last year he received NAA's "Presidents Award."

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