Ask the Expert: Dormant-Season Treatments

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Each year, vegetation managers race against the clock to complete planned treatment cycles during the foliar season. Several factors can impede productivity for this essential work, including weather delays, labor shortages and budget limitations. Skipping brush control treatments can lead to setbacks that have lasting effects on vegetation management programs. That’s why we connected with Josh Smalley of Alabama Power Company and Travis Rogers of Corteva Agriscience to discuss the impact of deferred maintenance and the benefits dormant-season applications provide to vegetation managers looking to achieve year-round vegetation control.

As a market development specialist with Corteva, Rogers has 15 years of experience working with energy companies, federal and state agencies, conservation groups and service contractors within rights-of-way and forestry industries. Respectively, Smalley is a utility arborist supervisor with Alabama Power Company who has managed contract tree crews for the maintenance of overhead powerlines for nearly a decade. Together, these two experts provide valuable insights concerning dormant-season applications and the ways in which they can enhance budget management, environmental sustainability and program productivity for vegetation managers across the country.

What is deferred maintenance and how does it impact vegetation management programs?

Josh Smalley (JS): Deferred maintenance is the choice that vegetation managers occasionally make to push some of their planned maintenance to a later date or season. While this decision is sometimes unavoidable due to budgetary constraints, manpower limitations or environmental factors, many studies have shown that as timing between maintenance cycles increase, costs increase as a result. As vegetation grows closer to the conductor, labor needs and trimming costs go up. Additionally, as the amount of biomass on the right-of-way increases, the cost of cleanup after a trimming activity increases as well.

What types of dormant-season applications can vegetation managers use and how do they work?

Travis Rogers (TR): Several types of dormant-season applications have proven effective for incompatible vegetation control during the fall, winter and spring months. Dormant-stem applications are probably the closest thing to foliar applications, especially when thinking about crew productivity. Backpacks or hydraulic equipment can be used to apply herbicides to the stems of woody plants throughout various sites containing low to high brush. They are best-suited to control woody plants with a stem diameter of 2 inches or less. Once applied to the stems, the herbicide is readily absorbed through the bark and translocated throughout the plant. 

Cut-stump treatments are recommended after hand-cutting operations for the removal of hardwood tree species and resprouting prevention. After hand-cutting, sawdust or plant debris should be removed from the cut surface before applying an herbicide mixture to the outer-top edge of the stump (cambium layer) as well as any remaining bark or exposed roots. 

JS: Another popular solution is a basal bark application, which involves treating 10-15 inches of the stems of undesirable species with an herbicide mix containing bark oil. This method is very effective and targeted.

Many vegetation managers also employ the hack-and-squirt method. Multiple hacks are made around the stem of the tree and an herbicide is applied directly into the cuts. This is a more labor-intensive procedure but yields good results in a very targeted manner.


Dormant-stem applications perform well on our system and work equally as well on woody herbaceous species, hardwoods and conifers.


On what types of plant species are dormant-season applications most effective?

JS: Dormant-season applications can be effective on nearly all undesirable species if applied correctly with the proper herbicide mix ratios. Dormant-stem applications perform well on our system and work equally as well on woody herbaceous species, hardwoods and conifers.

How do dormant-season applications impact budget management and the environment?

TR: Dormant-season applications can help balance out maintenance expenditures throughout the year while taking advantage of funding when it’s available. This approach to year-round vegetation control also can reduce the impact of budget fluctuations that occur at critical times of the year. 

How can dormant-season applications reduce public scrutiny for vegetation managers?

TR: When evergreen species are treated, they commonly turn brown after treatment. However, this happens gradually with dormant-season applications, whereas foliar-season applications often lead to rapid results. That’s why many vegetation managers use dormant-season applications in sensitive or highly visible areas to reduce public scrutiny.   


Given the treatment options and flexible application window of dormant-season applications, they can be used at any time.


When is the best time to initiate a dormant-season program?

JS: In my experience, the best time to initiate a dormant-season program is early in the year, or even the year before you plan to make applications in the field. Allow time to plan for it, set your budget up for it, and have conversations with licensed applicators and subject matter experts. Time spent on the front-end planning will make things much easier and more successful during and after the application process.

TR:Given the treatment options and flexible application windows of dormant-season applications, they can be used at any time. Our industry relies heavily on seasonal contract crews, which increases the importance of identifying estimated treatment acres each year.

How can vegetation managers identify the proper products or equipment to use?

JS: The best way to ensure that you are using the proper products and equipment is to reach out to subject matter experts in the industry. There are many great resources available in the herbicide application field. Contact your chemical providers to get recommendations on proper herbicides and mix rates, have conversations with licensed applicators in your area to get tips and ideas for equipment, or perhaps contract them to do your applications for you. Never be afraid to ask your industry peers for advice.

TR: Through years of research and field experience, Corteva has identified the equipment, products and application techniques needed to ensure dormant-season applications work. Garlon® 4 Ultra herbicide is a foundational herbicide for dormant-season work. Additional tank-mix partners can be added or recommended based on the goals and objectives of each vegetation management program. As the recommended adjuvants and application equipment can vary, I’d recommend contacting a Corteva vegetation management specialist in your area if you are interested in how these treatment methods can benefit your personal program.  

For more information on dormant-season treatments, application methods and product recommendations for your respective program, click here.


Expert Bios

Travis W. Rogers

Travis W. Rogers is a market development specialist for Corteva Agriscience within the Eastern U.S. Pasture & Land Management District. In his role, he supports 11 territory managers and serves as the interface between the commercial sales and R&D units. He has 15 years of experience working with energy companies, federal and state agencies, conservation groups, channel partners and service contractors within the rights-of-way and forestry industries. He is based in Charleston, South Carolina. 

Josh Smalley

Josh Smalley is a utility arborist supervisor with Alabama Power Company. After graduating from Auburn University with a BS in Forestry, he became a registered forester and ISA-certified utility arborist. In support of the Integrated Vegetation Management program employed by Alabama Power, he uses more than 13 years of utility vegetation management experience to manage the utility’s transmission LiDAR inspection program; provide planning and logistics support for the utility’s system-wide herbicide program; and oversee the acquisition and implementation of contracts for many of its vegetation management partners. He is based in Birmingham, Alabama.


™ ® Trademarks of Corteva Agriscience and its affiliated companies. State restrictions on the sale and use of Garlon 4 Ultra apply. Consult the label before purchase or use for full details. Always read and follow label directions. © 2021 Corteva.

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