Shrubs that continually send up new shoots after being cut back demonstrate a tenacious root system requiring specific methods for complete removal. Simply cutting the plant down often stimulates aggressive new growth, a survival mechanism known as suckering or resprouting. Achieving permanent shrub removal requires killing this underground root system, not just addressing the visible growth above the soil line. The goal is to eliminate the source of regeneration to prevent the shrub from ever returning, which can be accomplished through physical labor or targeted chemical application.
Initial Steps Before Applying a Killing Method
Before attempting to kill the root system, the shrub must first be cut down to a manageable size. The entire above-ground structure should be removed using loppers, a handsaw, or a chainsaw, leaving a stump typically six to twelve inches high. This remaining stump provides a handle for manual removal or a clear target for chemical treatment. Clearing the surrounding area of debris and loose soil is also important to expose the root flare, the base of the trunk where the roots begin to widen.
The surrounding soil should be cleared away to reveal the cambium layer, the living, thin tissue just beneath the bark that transports nutrients. This layer is the pathway that must be targeted, whether by mechanical severance or chemical application, to ensure the root system is effectively killed. Ensuring the work area is safe is also necessary, which includes contacting the local utility notification center, such as 811 in the U.S., a few days prior to digging to locate any underground lines.
Mechanical Removal of the Stump and Roots
Mechanical removal is the non-chemical option for eradicating the shrub, relying entirely on physically removing the root system. This process is labor-intensive but is preferred by those who wish to avoid introducing herbicides into their landscape. It is most effective when the soil is moist, which helps loosen the soil around the root ball.
The process begins by digging a trench around the base of the stump, extending out to where the main lateral roots radiate from the root flare. A mattock or grub hoe is effective for breaking up the soil and chopping through smaller roots. The goal is to expose the root ball and the thickest lateral roots, which can then be cut using a pruning saw or a reciprocating saw.
Once the lateral roots are severed, a heavy-duty pry bar or a stump jack can be used to leverage the stump and root ball out of the ground. It is important to remove the entire root crown and as much of the root system as possible. Left-behind root fragments from certain species can still produce suckers and lead to regrowth.
Chemical Treatments to Prevent Regrowth
Chemical treatment, specifically the cut stump method, offers a less strenuous alternative to physical digging and is effective at preventing regrowth. This technique relies on applying a concentrated, systemic herbicide directly to the fresh cut surface of the stump. The active ingredients of choice are glyphosate or triclopyr, which are translocated down to the root system, killing it.
The timing of the application is important for success; the herbicide must be applied within minutes of making the final cut, as the stump’s vascular system begins to seal off immediately. For water-soluble herbicides like glyphosate, a concentration of about 50% is recommended, achieved by mixing high-concentration product with water. Triclopyr is available in formulations that can be mixed with basal oil for application and is often used for certain woody plants.
The herbicide should be painted directly onto the cambium layer, the thin, moist ring just inside the bark, as this tissue transports the chemical to the roots. For smaller stumps, it is easier to treat the entire cut surface, ensuring thorough application. For larger stumps, an alternative method is to drill several downward-slanted holes into the stump top and pour the concentrated herbicide directly into these reservoirs.
Safety Precautions and Debris Disposal
Adopting proper safety protocols is necessary regardless of whether mechanical or chemical methods are chosen. When handling herbicides, wearing appropriate personal protective equipment (PPE), such as chemical-resistant gloves, long sleeves, and eye protection, prevents skin and eye contact. Care must be taken during chemical application to avoid overspray or drift onto surrounding desirable plants, as these systemic products are non-selective.
When using cutting tools like chainsaws or reciprocating saws, safety glasses, hearing protection, and sturdy footwear are recommended. Before beginning any digging, calling 811 is necessary to prevent accidentally striking underground utility lines.
Once the shrub is removed or killed, the debris must be handled appropriately. Untreated wood and branches can be chipped for mulch or hauled away for composting, depending on local guidelines. However, plant material treated with a systemic herbicide should not be composted or chipped for reuse as mulch near edible plants, as the herbicide may persist. Treated material should instead be bagged and disposed of according to local waste management regulations for chemically treated garden waste.