Basal Bark and Cut-stump Treatments
Woody plants and brush are oftentimes aggressive and spread quickly into unwanted areas. Invasive species interfere with natural habitats; in addition, undesirable vegetation can become a safety hazard in utility and transportation rights-of-way, cause damage to structures, and crowd fence rows in pasture settings.
The removal of undesirable trees and brush can be time-consuming and a challenging project to complete. Oftentimes the size of the plant, or its surroundings, make a broadcast application impractical and many species will resprout from the stump following mechanical removal. In these instances, the treatment of individual plants, or specific species, is the best method of control. To amplify efficacy and enhance productivity, Alligare recommends the following information and best practices for your basal bark and cut-stump applications.
BASAL BARK
This control method is for woody vegetation and includes mixing herbicide or an herbicide solution with oil to carry the product through the bark and vascular tissue into the root system of the plant. To maximize efficacy, the solution must be sprayed onto the lower 12 inches of the stem or trunk with thorough application down to the soil line, including all exposed root flares, and around the entirety of the plant. Plant stems up to six inches in diameter are ideal for basal treatments. For multi-stemmed species, all stems should be treated. This method allows the applicator to selectively treat individual plants without causing injury to neighboring vegetation.
When using basal treatment mixtures, the herbicide needs to be an ester formulation. Amine salts will not mix with oil and do not penetrate the bark of the plant. Alligare recommends mixing triclopyr 4 ester at 25 percent in oil. In the past, diesel was the most commonly used oil carrier, but the current recommendation is to use commercially available basal oils as they are more environmentally sound. As a user-friendly option, Alligare offers short-filled, 15-gallon drums of basal oil and dye that contain 11.25 gallons of the carrier oil needed for treatment.
CUT-STUMP
Cut-stump applications involve cutting down a targeted plant and then applying an herbicide solution directly to the stump surface. This is an effective way to prevent regrowth of woody species and large vines. All stems should be cut and treated on multi-stemmed species. It is best practice to cut as close to the ground as possible, with the remaining stump measuring one to two inches in height. The entire cut surface should be treated for stumps and stems smaller than six inches in diameter. For larger species, the most critical area of the stump to treat is the cambium, which is the layer just inside the bark. The entire circumference must be treated.
The herbicide should be applied immediately after cutting. The most common solutions involve mixing glyphosate or triclopyr amine at a 50 percent rate in water. If there are any delays in treatment, Alligare recommends a 25 percent solution of triclopyr 4 ester in basal oil be used. Like the basal bark technique, the entire root collar (bark area) and any exposed roots must also be treated.
APPLICATION TIMING
Basal bark and cut stump treatments can be applied at any time of the year. However, it is not recommended in the early spring when plants are pulling resources from the roots and experiencing strong upward sap flow. Applications should also be avoided if the base is covered in snowfall or surrounded by rainwater. The solution will be weakened and no longer have the ability to penetrate the bark.
EQUIPMENT NEEDED
For both basal bark and cut-stump techniques, a backpack sprayer or handheld, pressurized spray bottle is the preferred delivery system for the herbicide solution. For cut-stump applications, you will first need a pruning tool such as a chainsaw, hand saw, shears, or a sharpened machete. Cut-stump treatments may also be applied with a paintbrush. Always wear the PPE required by the herbicide label and recommended by the tool manufacturer.
Enloe, S. (2021a, March 26). Basal bark herbicide treatment for invasive plants in pastures, natural areas, and forests. Alabama Cooperative Extension System. https://www.aces.edu/blog/topics/forestry-wildlife/basal-bark-herbicide-treatment-for-invasive-plants-in-pastures-natural-areas-and-forests/
Enloe, S. (2021, May 21). Cut stump herbicide treatments for invasive plant control. Alabama Cooperative Extension System. https://www.aces.edu/blog/topics/forestry-wildlife/cut-stump-herbicide-treatments-for-invasive-plant-control/
Enloe, S. Image of cut stump with basal oil. https://www.aces.edu/blog/topics/forestry-wildlife/cut-stump-herbicide-treatments-for-invasive-plant-control/ (2023, August 15.)
