Sumac varieties, particularly the aggressive, colonizing types like Staghorn Sumac (Rhus typhina), are difficult to eliminate. This plant spreads primarily through an extensive network of shallow, lateral root systems known as rhizomes, not just by seed. When the main trunk is damaged or removed, the plant perceives a threat and rapidly activates dormant buds along these underground roots, causing a proliferation of new shoots to emerge far from the original plant. Successful eradication requires a sustained, multi-step approach that combines physical removal of the main body with targeted chemical application to interrupt the root system’s ability to regenerate. Simply cutting the tree down will stimulate the plant to grow back with greater vigor, making a strategic plan for root elimination necessary.
Eradicating the Main Trunk and Root Crown
Cutting the main trunk down close to the ground, using a chainsaw or sturdy loppers, is the first part of this process. This action is merely preparation, as cutting alone triggers the plant’s defense mechanism, encouraging suckering from the roots. To minimize the energy reserves available for future growth, the remaining stump and root crown must be dealt with immediately. Physically digging out the entire stump is an option, though it is highly labor-intensive and often leaves fragments of the far-reaching rhizomes behind. A less strenuous mechanical alternative is stump grinding, which pulverizes the stump down to several inches below the soil line. The primary purpose of removing the main trunk is to create a fresh, accessible surface for the most effective eradication method: systemic herbicide treatment. This application must happen within minutes of the cut to ensure maximum absorption before the plant’s natural defenses seal the wound.
Using Chemical Treatments for Complete Elimination
Systemic herbicides are the most effective tool for destroying the extensive root system. These chemicals must be applied directly to a fresh wound so the plant can transport the active ingredient downward through the vascular system to the roots.
Cut-Stump Method
The “Cut-Stump” method is the most targeted approach, requiring the application of a concentrated herbicide directly to the cambium layer of the freshly severed trunk. The cambium is the thin, active layer just beneath the bark. For trunks larger than four inches in diameter, only the outer ring of the cut surface needs to be treated, as this is where the vascular tissue is located. Effective chemicals include concentrated Glyphosate or Triclopyr, which should be applied with a small brush or a low-pressure sprayer immediately after the tree is cut. A 50% concentration is often recommended for this application to ensure the chemical moves throughout the rhizomes.
Basal Bark Treatment
Another effective technique for smaller stems or when cutting is not immediately feasible is the “Basal Bark” treatment. This involves applying an oil-soluble herbicide, such as Triclopyr ester mixed with a specialized oil carrier, directly to the bark around the lower 12 to 18 inches of the intact trunk. The oil carrier allows the herbicide to penetrate the bark and reach the cambium, translocating the poison into the roots without requiring a fresh cut. Applying chemicals in late summer or early fall is optimal because the plant is actively moving carbohydrates downward to the roots for winter storage, maximizing the herbicide’s transport to the entire root system.
Managing New Shoots and Preventing Spread
Even after successfully treating the main trunk, the latent buds on the widespread root system will inevitably produce new shoots, often emerging several feet from the original location. Continuous monitoring and follow-up treatment are required to exhaust the root’s remaining energy reserves. Ignoring these new shoots allows the roots to photosynthesize and replenish the reserves.
Chemical Spot-Treatment
Managing these suckers involves either chemical spot-treatment or consistent mechanical removal. Small, scattered shoots can be treated with a foliar spray of a diluted herbicide, such as a 2-3% aqueous solution of Triclopyr, once the leaves have fully developed. The leaves must be large enough to absorb the chemical, but the shoots should still be small, ideally under three feet tall.
Mechanical Removal
Alternatively, repeated cutting or mowing of the new shoots can starve the root system over time by preventing photosynthesis. This mechanical method must be done consistently, often twice in a single summer. It may take several years to fully deplete the underground rhizomes. A common mistake to avoid is tilling the area, as breaking the shallow roots into smaller pieces simply creates more root fragments, each capable of sprouting a new sumac colony.