The Bradford Pear (Pyrus calleryana) is an ornamental tree often problematic due to its weak branch structure and aggressive root system. Grafted onto vigorous Callery Pear rootstock, it is notorious for sending up thorny, unwanted sprouts from its roots, known as suckers. When the main tree is removed, the remaining root system contains significant energy reserves and will attempt to regrow. Therefore, actively killing the roots is necessary to prevent persistent sprouting and invasive spread, focusing on transporting a killing agent directly into the root network.
Preparing the Stump for Root Treatment
The process of permanently eliminating the root system begins with the correct removal of the main trunk. Cutting the tree as low to the ground as possible minimizes the visible stump and maximizes the root tissue available to absorb the treatment. The fresh-cut surface must be treated immediately after felling, ideally within minutes, before the wood dries and the vascular system seals itself.
For effective absorption, expose the cambium layer, the thin, living ring just beneath the bark. This layer transports nutrients and water throughout the tree, including down into the deep roots. Treatments are most effective when applied to this outer ring, rather than the inactive heartwood in the center. Alternatively, drill a series of downward-slanted holes around the outer edge of the stump to hold the killing agent.
Chemical Methods for Root Destruction
Chemical application is the most reliable method for ensuring the entire root system dies and does not produce suckers. Herbicides specifically formulated for woody plants and stump killing must be used, typically concentrated products containing Triclopyr or Glyphosate. These systemic herbicides are designed to be translocated, meaning they travel from the application site through the tree’s vascular system to the farthest reaches of the roots, effectively killing them.
A common technique involves painting or spraying the herbicide concentrate directly onto the exposed cambium ring of the freshly cut stump. This method, often referred to as a “cut-stump treatment,” ensures the chemical is absorbed into the transport system, maximizing its reach into the root network. For larger stumps, drilling holes approximately one inch deep and filling them with concentrated herbicide provides an alternative route for absorption. Safety is paramount, requiring the use of protective gloves, and care must be taken to prevent runoff or overspray onto the surrounding soil or desirable plants.
Concentrated Glyphosate or an oil-soluble Triclopyr ester should be used according to the product label’s instructions for cut-stump application, which is often a much higher concentration than foliar spray. Surface application of herbicide to the soil surrounding the stump is ineffective and poses a risk of environmental contamination, as the chemical must be taken up by the plant’s living tissue. The best time for this application is generally in the late summer or fall when the tree is naturally moving resources, including the herbicide, down into the roots in preparation for winter.
Non-Chemical Approaches to Root System Death
Homeowners seeking to avoid synthetic herbicides have several non-chemical options for root destruction, though they typically require more time and labor.
The most definitive non-chemical approach is complete physical removal. This involves grinding the stump several inches below the soil line and digging out all accessible lateral roots. While highly effective, this process can be difficult and may still leave small root fragments capable of sprouting.
Smothering or solarization is a passive method that starves the roots of light and oxygen, accelerating decay. Cover the remaining stump and the entire root zone with a thick, opaque plastic sheet or tarp, securing the edges to block all sunlight and trap moisture. Over a period of several months to a year, this technique encourages fungal and bacterial activity, leading to the natural decomposition of the wood and roots.
The use of high concentrations of common substances like rock salt, Epsom salt, or fertilizer is sometimes suggested to kill the stump. These materials work by drawing moisture out of the wood tissue, causing dehydration, or by promoting rapid decay through excessive nitrogen. However, these methods are unreliable for killing the deep root system and carry a substantial risk of creating a toxic zone in the surrounding soil, potentially damaging nearby healthy vegetation for years.
Dealing with Persistent Root Suckers
The emergence of persistent suckers, small sprouts growing directly from the lateral roots, is a frustrating aspect of Bradford Pear removal. These are common because the ornamental Bradford Pear is a grafted variety, and the aggressive Callery Pear rootstock is programmed to sprout once the main trunk is removed or damaged. If the initial stump treatment was unsuccessful, the root system retains enough energy to repeatedly send up new shoots.
Simply mowing or cutting the suckers off is counterproductive, as the root system interprets this action as damage and responds by producing even more sprouts. The most effective strategy is to treat the suckers directly with a systemic herbicide, such as a concentrated Glyphosate solution, when they are actively growing. Paint or wipe the herbicide directly onto the cut surface of a sucker immediately after it is clipped, allowing the chemical to travel down into the root that produced it. Repeated cutting and treating of every new sprout is necessary to eventually exhaust the extensive energy reserves stored in the root system.