The past year presented countless challenges for vegetation management professionals. Weather patterns are always unpredictable, but few could have anticipated the budget limitations and labor shortages that resulted from the COVID-19 pandemic. And while these issues posed major roadblocks for utility and roadside vegetation management teams, they definitely didn’t prevent trees and tall-growing brush from developing along roadways or utility right-of-way corridors.
When plant species are allowed to grow freely, they block visibility on the roads, fracture infrastructure and inch closer to sensitive electrical transmission lines. As vegetation continues to grow, it increases maintenance requirements for vegetation managers. This can cause setbacks most programs fail to overcome without the help of additional funding and/or skilled labor staffing. But dormant-season treatments can enhance brush control programs without the need for significant budget or workforce expansion.
While usage rates will vary by target vegetation and brush density, the following treatments are effective on most woody species in winter or early spring:
Dormant-Stem Treatment
For brush measuring up to 10 feet in height or 2 inches in diameter, dormant-stem treatments can be applied from fall leaf senescence until 25% plant leafout in the spring. Treatments are applied to the stems and trunk of targeted plant species, and the use of basal oils can also improve herbicide penetration for enhanced coverage and optimum results.
Basal Bark Treatment
Low-volume basal bark treatments are best suited for areas with no more than 500 stems per acre. Using a very targeted application method combined with a selective herbicide mix, vegetation managers can target individual stems no larger than 6 inches in diameter by treating the lower 12-15 inches of a targeted plant stem’s base. Once the herbicide mix is absorbed through the bark, it translocates to the roots and stems, eliminating the risk of resprouting or vegetation regrowth. This treatment method is not recommended for environments in which snow or water prevent spraying to the ground line.
Basal Cut-Stump Treatment
When treating woody plants that have been individually cut, a selective herbicide mixture can be applied to the cambium layer as well as any remaining exposed bark or roots to prevent resprouting. The same mixture used for low-volume basal bark treatments can be used for basal cut stump treatmnets. One of the biggest benefits of using this mixture is it doesn’t have to be applied immediately after the stem is cut.
Field research from Corteva Agriscience has shown that delaying routine maintenance by a single growing season can double the cost of vegetation maintenance in the future. But with the help of dormant-season treatments, vegetation managers can avoid these economic setbacks. Best of all, the pump or backpack sprayers most commonly used for these types of applications are easy to use and treatments can be applied relatively quickly.