AASHE Campus Sustainability Hub

The Natural Herbicides Project focuses on addressing the issue of the usage of chemical herbicides with detrimental health and environmental impacts on- and off-campus. Our team developed an effective natural herbicide based on our award-winning research and then created materials focused on teaching students and community members how to make and use this herbicide. We have led classes teaching current and aspiring gardeners how to manage their garden weeds in a sustainable manner, helped student organizations control weeds in their gardens, and reached out to students about how they can choose to use products that are both natural and effective. We also conducted an organic lawn maintenance trial demonstrating that campus lawns can be effectively maintained using organic methods.

The issue of weed control creates a high demand for herbicides with global pesticide usage approximating 5.2 billion pounds and herbicide usage accounting for the largest portion of overall pesticide usage (Grube et al. 2007). In the United States, 13 to 20 million acres are treated annually with 18.7 million pounds of the common nonselective post-emergent (POST) herbicide, glyphosate (EPA 1993). The Georgia Institute of Technology (Georgia Tech), along with many other universities, uses this herbicide for lawn maintenance. Based on participatory action research in the Atlanta community, low-income community gardeners also use chemical herbicides to control weeds effectively at a low cost, prohibiting these gardeners from gaining organic certification and decreasing the resiliency of their gardens. Georgia Tech students pursuing a vocational degree through the EXCEL program are likely to become future community gardeners who may also end up using chemical herbicides. However, the human health and environmental effects of traditional synthetic herbicides have attracted increasing negative public attention, contributing to a high demand for organic products produced without the usage of synthetic herbicides. The World Health Organization (2015) classified glyphosate as “probably carcinogenic to humans.” Landscapers and gardeners need a solution that effectively controls weeds at a low cost but does not have the negative health and environmental impacts of traditional herbicides.

The primary goal of the Engineers for a Sustainable World Natural Herbicides Project is to encourage a shift away from the usage of chemical herbicides, synthetic solutions used to control weeds that can have extensive negative health and environmental impacts. A secondary goal is to empower community gardeners and aspiring community gardeners in Georgia Tech’s EXCEL program to maintain their gardens in a safe and sustainable manner. A last goal is to instill the idea of sustainable consumerism in Georgia Tech students by demonstrating that they do have the choice to choose natural products without sacrificing on performance.

One last, broader goal, is to provide students on other campuses (starting with members of other Engineers for a Sustainable World chapters) with the resources and information they need to start similar projects achieving the same goals to spread the project's impact.

Our team has developed a natural weed control solution that has exemplified higher efficacy (weed control) and requires fewer reapplications than existing organic herbicides, helping remove the cost barrier that often prohibits gardeners and landscapers from using existing safer weed control options. We have conducted experiments showing the improvements in weed control offered by our herbicide to be statistically significant. In 2012, I conducted the first experiment, which was focused on determining what combination of organic ingredients with herbicidal (weed-killing) properties was most effective in controlling weeds. This experiment, which received international recognition from the Google Science Fair, The Global Journal, and Scientific American, showed that a combination of d-limonene (an orange oil derivative) and acetic acid exhibited the highest weed control. Based upon this result, I started a project group in the Engineers for a Sustainable World student organization at the Georgia Institute of Technology (Georgia Tech) in 2014. Our project group developed a partnership with the Georgia Tech Landscape Services Department and conducted an organic lawn maintenance trial on a lawn area at the university, demonstrating that organic methods could effectively be used to control weeds. Students Francis Nguyen, Lindsey Tracey, Jamie Curtis, and Andrew Vidovich were involved in conducting this trial, which I led. The Landscape Services Department was interested in obtaining more information on the cost of our solution after the trial, so we conducted a second research study focused on maximizing the cost-effectiveness of our solution by determining the most effective ratio of the ingredients and how much it could be diluted. We adhered to the standards of the academic journal Weed Technology when conducting this experiment to ensure the validity of the results. Students Francis Nguyen, Lindsey Tracey, Loan Nguyen, Hao Tran, Nick Padula, Stephanie Varughese, Lauren Achey, and Catherine Schlueter. helped conduct this study, which I led. Our team then became more focused on community outreach and began distributing samples of our natural herbicide solution and giving classes to gardeners and aspiring gardeners through the Atlanta Community Food Bank County Gardens Leadership Program and Georgia Tech’s EXCEL program. These classes focused on how to make and safely apply a homemade natural herbicide solution, as well as on other organic practices discouraging weed growth. Nick Padula, Lauren Achey, and I led these classes, while the aforementioned team members helped prepare for them. In addition, Francis Nguyen compiled a pamphlet providing guidelines on how anyone could make and use natural herbicides, and I created a guide for other Engineers for a Sustainable World chapters to start similar projects at their universities (focused on the community outreach aspect of the project, as they would not need to replicate the research study stage. We also helped other student organizations focused on gardening control weeds using our solution. Lastly, we created a proposal for addressing food and water issues in our university’s city of Atlanta based on our community outreach work and entered the Engineers for a Sustainable World Resilient Community Design Challenge with this proposal. In this challenge, our team received the First Place Award, and I received the Best Presenter Award. With the grant we received, we are currently implementing our proposal, which primarily involves continuing to work with and expand our relationships with gardeners on- and off-campus. We also set up a booth at Georgia Tech’s Earth Day Celebration, at which we gave out samples of our herbicide and talked to students about how they can make a difference by choosing safe, effective products. We are now planning to build upon our existing relationship with Georgia Tech Landscape Services to work towards campus-wide organic weed control. *If anyone is interested in replicating our project, we can provide our guidebook explaining both how to make a homemade natural herbicide based on our research and how to develop campus and community partnerships to encourage organic weed control practices.

The project has taken five years to date, and we hope to continue to build upon our past work and maintain our relationship with multiple stakeholders on Georgia Tech’s campus and in the local community for years to come. A timeline is provided below:

March 2012: First Experiment August 2014: Started Engineers for a Sustainable World Natural Herbicides Project Team January-May 2015: Conducted organic lawn maintenance trial at Georgia Tech August-December 2015: Conducted second experiment January 2016: Began working with the Atlanta Community Food Bank and Georgia Tech’s EXCEL program to teach student and local gardeners about organic weed control April 2016: Engineers for a Sustainable World Resilient Community Design Challenge August 2016-May 2017: Continued to teach classes and work collaboratively with gardeners. April 2017: Georgia Tech Earth Day Celebration booth Current: Continuing to work with gardeners and towards campus-wide organic weed control Fall 2017: Planned film screening of Vanishing of the Bees (a film showing some of the effects of chemical herbicide use)

The cost of the first experiment is not recorded, and the experiment was funded using personal finances.

The cost of the organic lawn maintenance trial was $746. This trial was funded using $500 of funding from a Georgia Tech Stamps President’s Scholarship Program enrichment grant and $150 funding from Engineers for a Sustainable World.

The cost of the second experiment was $900, and this experiment was funded using the $1500 Georgia Tech President’s Undergraduate Research Award.

The current cost of making one gallon of our natural herbicide solution (a recurring cost of the community outreach portion of our project) is $15.74/gallon. The cost of the spray bottles used to contain herbicide samples (another that we give to student and local gardeners is $.99/bottle. Our current community outreach work is funded by a $3000 grant we received from the Engineers for a Sustainable World Resilient Community Design Challenge and a $500 Engineers for a Sustainable World Small Project Grant.

Results of the project include the interest of Georgia Tech’s Landscape Services Department in using a natural herbicide, the awareness of students at Georgia Tech that better weed control options than chemical herbicides exist, and the adoption of organic methods by student and local gardeners.

One of the most valuable lessons I learned from this project is to focus on developing a strong understanding of your audience and meeting audience needs. The first time my team taught a class to Atlanta Food Bank gardeners, our presentation and brochures was not appropriately tailored to the audience, which consisted largely of elderly gardeners. Our font size was too small, we spoke too fast, we included images of our herbicide’s effects in lawn settings rather than garden settings, and we provided excess information about our project’s history that was not relevant to the gardeners. After we improved our understanding of our audience, we revised our presentation before our next class with the Atlanta Food Bank, and we created modified brochures that we distributed to the individuals who had attended our first class. At the same time, when we taught classes through Georgia Tech's EXCEL program, we worked to ensure that we taught the material in a way that made sense to students who learn in a different way as the EXCEL program is a special education vocational college option. For anyone trying to start a project similar to ours focused on teaching how to make and use natural herbicides and other weed control methods (and/or working towards sustainable weed control on campus lawns and generating awareness of the importance of choosing safer products amongst students), we would strongly advise the perspective of every audience we considered. Different outreach materials should be developed for different audiences. With a project focused on changing mindsets and/or institute practices, this is crucial.

• Grace Brosofsky - Project Leader, Natural Herbicides | Georgia Institute of Technology

• Link: Natural Herbicides Facebook Page
• File: Informational Pamphlet