Most woody plants are susceptible to chemical application in the form of herbicides. Effectively controlling woody encroachment with chemicals depends significantly on using the correct chemical at the right time and at the proper rate. Environmental factors like precipitation, temperature, and wind will also affect the success of chemical applications.
Chemicals can be applied in several ways, including broadcast spraying, spot spraying, and aerial spraying. Combining chemical and mechanical practices has been shown to have even better success. For example, after cutting, stumps can be treated to prevent resprouting or woody plants can be cut and then sprayed with herbicides.
While chemical control can be an effective and economical way to manage woody plants results can vary because many brush species are tolerant to some herbicides. Find chemical application recommendations, safety procedures, and other information in the K-State Extension Chemical Control Handbook.
Application Methods
Spot spraying can be an effective method for land managers to selectively target invasive plants and effectively treat them without harming other beneficial plants. When treating with herbicide, be sure to read and follow the recommendations. Almost all herbicides on the market have spot recommendations on the label.
Broadcast spraying is another management option. Unlike spot spraying, which targets an isolated plant or problem area, broadcast spraying applies herbicide to an entire area. When deciding whether to use broadcast spraying, it is important to consider how a broadcast application may unintentionally reduce preferred livestock forage, necessary wildlife cover, and other desired plants.
Aerial spraying may be more effective in some situations, including widespread or dense infestations or difficult terrain. For instance, rugged terrain may prohibit spot spraying applications when ground rigs can not access an area. Another advantage of aerial spraying is the ability to spray when ground conditions are too wet. In addition to traditional aerial application methods, new technologies, including drones, are being used to apply herbicides.
Pelleted herbicide is another option for controlling invasive woody plants. Pellets dissolve in the soil and release the herbicide into the plant’s root zone, where it’s absorbed during active plant growth. This application is most appropriate during wetter seasons when the pellets dissolve and can work more effectively.
Safety Considerations
Chemicals that can kill plants can also cause illness in humans. It is essential to wear personal protective equipment when mixing, loading, applying, or disposing of chemicals. Always wash your face and hands thoroughly with soap and water after removing personal protective equipment and returning to normal activities. Personal protective equipment may include hat, goggles, long-sleeved clothes or overalls, gloves, rubber boots, and even a respirator. Make sure to read all chemical labels thoroughly to understand the proper rate of application, and also what safety precautions are needed.
Hiring Help
In some areas, contractors are available to conduct spray applications (spot, aerial, etc.). Finding a contractor that has done work in your area, possibly for a neighbor, is a great way to find a contractor. You can also search our contractor list. Below are some topics, with a few example questions, to discuss with a potential contractor.
References
- Is there anyone locally you’ve worked with who is willing to provide a recommendation or discuss their experience with you?
Experience
- How long have you been doing this work?
- Do you have experience with projects similar to this one (e.g., removing similar species, utilizing similar machinery, etc. )?
- Have you worked on jobs that involved this assistance program and its specific requirements, or something similar, in the past?
Work Plan
- What is your plan for completing the project?
- What equipment will be used?
License and Insurance
- Are you or your company licensed?
- Do you carry liability coverage for any damage that may happen while on my property?
Cost Estimate
- Can you provide an estimated cost or cost range for this project?
- Please be specific about what is and is not included within the estimate.
- Please include information about required deposits and when all payments are due.
Timeline
- When will you be available to work on this project?
- How long do you anticipate the project will take to complete?