Campsis radicans, or Trumpet Vine, is admired for its showy, trumpet-shaped flowers that attract hummingbirds. This woody, deciduous vine is native to the southeastern United States, but its ornamental appeal belies a highly aggressive nature. It spreads rapidly through self-seeding and extensive underground runners that sprout new shoots far from the parent plant. Controlling this vine requires a persistent approach that addresses both the visible growth and the resilient root system.
Removing the Main Plant Structure
The first stage involves eliminating the bulk of the above-ground growth to prepare for treating the root network. Use a sturdy saw or loppers to cut the main vine trunk as close to the ground as possible, severing it completely from the roots. Wear gloves and long sleeves, as the vine’s sap can cause skin irritation.
If the vine is climbing a structure like a house, fence, or tree, caution is necessary. The vine uses aerial rootlets to adhere strongly, and ripping it off a building can damage paint, siding, or mortar. Instead, cut the vine into manageable sections and allow the attached pieces to dry out and die naturally before carefully scraping them away. Removing the foliage starves the roots of energy created by photosynthesis, making final eradication methods more effective.
Eradicating Root Systems and Suckers
Addressing the root system is the most challenging part of managing Campsis radicans, as the plant’s vigor stems from its extensive underground network. The roots spread widely, and any small fragment left behind can easily regenerate into a new plant. This requires either sustained physical removal or the strategic application of a systemic herbicide.
Physical Removal
Manual removal involves carefully digging out the main taproot and tracing all lateral roots thoroughly. The vine is proficient at sprouting from root segments, so every piece of root material must be removed to prevent regrowth. This method is labor-intensive and may require repeated effort over several seasons to exhaust the root reserves. If the area is too large for digging, persistent mowing or cutting down new shoots immediately as they appear will eventually deplete the energy stored in the roots.
Chemical Treatment
A more direct way to destroy the entire root system is through the targeted application of a systemic herbicide, which travels through the plant’s vascular system down to the roots. The “cut-and-paint” method is recommended for established, woody vines and minimizes the impact on surrounding desirable plants. Immediately after cutting the main vine trunk near the soil line, a concentrated systemic herbicide, such as glyphosate or triclopyr, is painted directly onto the fresh cut surface. The plant’s active vascular system draws the chemical down into the root crown and runners.
Timing this chemical application is a factor in its success, with late summer or early fall generally considered the optimal period. During this time, the vine actively transports carbohydrates downward to the roots in preparation for dormancy, maximizing the herbicide’s translocation to the subterranean parts. Always read and follow the product label instructions precisely, especially concerning concentration and safety precautions. Products containing triclopyr can offer a potent alternative, but they may persist in the soil for a longer period compared to glyphosate, a detail to consider if you plan to replant the area soon.
Preventing Recurrence and Future Spread
Even after the main plant is removed and the roots are treated, long-term vigilance is necessary to ensure the vine does not return. The trumpet vine spreads easily via seed dispersal and the emergence of suckers from remaining root fragments. Regular monitoring of the site is essential for intercepting new growth before it can re-establish the root system.
To manage underground spread from neighboring properties or residual roots, installing a physical root barrier can be effective. This involves burying a solid, non-degradable material, such as heavy-duty plastic sheeting or metal flashing, vertically into the ground to a depth of at least 10 to 12 inches. The barrier should completely encircle the area or be placed along property lines to block the lateral movement of runners.
New seedlings should be hand-pulled as soon as they are identified. Any new suckers emerging from the ground, which indicate a surviving root fragment, must be promptly dealt with by pulling them out or treating the small cut stem with a dab of herbicide. Consistent effort in removing new growth prevents the vine from performing photosynthesis and replenishing root energy stores, ultimately leading to the plant’s exhaustion.