Kacy Gao announces the expansion of the project at Civic X EarthFest.
First Drexel, tomorrow Philadelphia, eventually — the world. Drexel University has moved to an organic turf management model across all of the University City Campus and will eliminate synthetic herbicides and fertilizers, just over a year after a group of students started a pilot program to test the efficacy of the model. But the roots for the project took hold before that program, and work doesn’t stop with the project’s expansion.
In the spring of 2022, Kacy Gao, biological sciences ’25, began to connect the first dots that would lead to Drexel’s campus-wide switch to organic turf management with the founding of Toxic Free Philly Drexel, a committee within Drexel EcoReps. Gao connected with the citywide organization Toxic Free Philly about getting students involved in the group’s advocacy for Philadelphia’s Healthy Outdoor Public Spaces Law (HOPS), which bans toxic synthetic herbicides on city grounds in favor of organic land management.
“I thought that Drexel’s successful transition would definitely be key in advocating for the enforcement of the law, because it would show that a large city institution can do it, so we came up with the idea of data-driven advocacy,” Gao said. “We thought that by looping in students with this research, it would make Drexel administrators more receptive to the idea and more confident in the organic turf transition.”
Toxic Free Philly Drexel was the engine for the student research portion, and they worked closely with Drexel’s Grounds team to implement the changes and research. The Drexel students got connected with Re:Wild Your Campus, a national organization that already works to eliminate synthetic herbicides from college campuses. To help with research and securing funding, Gao approached Anneclaire De Roos, PhD, professor and interim chair of the environmental and occupational health department in the Dana and David Dornsife School of Public Health, who is on the advisory board for the city’s HOPS law.
Several connected dots and hundreds of hours of research and hard work later, Drexel has officially moved to a fully organic turf management program. Gao thought it would take three to five years to have enough soil chemistry data to support moving to a campus-wide application of the project, so the move was a pleasant surprise.
Long-term, moving to an organic model can benefit the University as well as the environment. In other campuses that have moved to organic models, costs have decreased over three to five years due to decreases in fertilization and irrigation needs.
“I'm interested to see where this goes, and the students made it happen,” De Roos said. “I also applaud Drexel for taking notice of what was happening and realizing we don't need synthetic herbicides. It’s better, not only for health, but also for the environment, in situations like this where it’s not necessary to use synthetic herbicides.”
The organic turf program isn’t just about eliminating synthetic herbicides and fertilizers — it’s about outcompeting the weeds by promoting stronger turf growth, Gao said. This includes organic fertilizers like gypsum or changing practices like different ways of overseeding and aerating the turf, or even just replacing synthetic herbicides with organic pesticides. Drexel Grounds also experimented with irrigation techniques throughout the pilot project.
Drexel Park and Lancaster Walk served as the test sites for the research project, in which Drexel Park received the organic turf management methods and Lancaster Walk served as a control site. Drexel’s Grounds Maintenance Director Scott Dunham suggested Lancaster Walk because it would get a similar amount of foot traffic and sunlight. The student research team outlined each area in a grid and measured a species-area curve to determine baselines for what sample size would be representative of the species of flora in the area.
“Obviously, getting data is important because that's how we back up our claims and justify having organic as opposed to conventional management,” said Rahul Inaganti, environmental studies & sustainability ’25, who is involved with Toxic Free Philly Drexel and has attended research conferences to present the project. “Creating that research procedure was kind of difficult at first, because there's so many ways to do it, but once we narrowed it down, it came together during those field days when we would see how the data collection translated to trends.”
Though De Roos and Grounds provided input, the students of Toxic Free Philly Drexel largely developed their own research methods. The students used the Braun Blanquet method to conduct their turf density/weed coverage research, which involved tossing a one meter by one meter square of PVC pipe onto their test sites, following random coordinate generation. Then, the researchers decided how much of the square was filled by turf, how much was filled by weeds and how much was bare soil.
“It takes a lot of communication between us because we had to be on the same page as to what a weed is and what we established as bare soil,” Inaganti said. “We communicated with our fellow students and Drexel Grounds’ [Assistant Director] Tony Gale, who came with us on a research day to verify what we thought of each quadrant and make sure we were doing it in accordance with how Grounds would do it.”
They recorded turf density and weed prevalence and conducted student surveys, while Grounds members continued with soil sampling for annual soil health measures, as they normally do.
“They also keep track of what [herbicides and fertilizers] they use throughout the year and when they use it, so we swapped out seven synthetic turf management applications with seven organic turf management applications,” Gao said.
Over the year, there was increased turf density at Drexel Park and a decreased soil pH, both of which boil down to mean that there was less bare soil and fewer unwanted weed species. This proved the efficacy of the organic turf management methods and set the stage for the entire campus to go organic.
"One thing that surprised me was some of the immediate differences between the sites,” De Roos said. “As you would expect, the organic site did immediately have more weeds than the conventionally managed site, but that got more similar as the season went on. As you manage the soil quality over time, it stabilizes.”
There was a slight increase in clover, which is counted as a weed, but the group has found that people generally don’t feel negatively about clover.
“What was requested by Facilities was the proof that they can maintain a decent turf, so we switched some of the questions to be more about a perception of the aesthetic quality of the area, and the perception of the turf and how it looks,” De Roos said. “What we found doesn’t surprise me. Students want some place to sit out on the grass, and they’d probably feel better about it if there’s not chemicals being sprayed right there.”
Going forward, they’ll continue to take the same weed prevalence and turf density data at Drexel Park and Lancaster Walk to keep getting longitudinal data, and student surveys will cover opinions on green spaces. There will be continued collaboration with Drexel Grounds for research to see how successful the program is and outreach to students and the community for feedback.
“Students are going to be using the green spaces the most, so we want to know their opinion of it,” Inaganti said. “As much as we've talked about students and what they think of our work, I think it's also important to highlight the Powelton and Mantua communities because outside of Drexel students and Grounds staff, th ey're the ones who use Drexel Park and Lancaster Walk the most, whether that's for family events or just walking their dog.”
Inaganti and other students involved in the research have presented at a few conferences to share their organic findings. At AESS, Inaganti connected with students from Emory University, who are conducting similar research and trying to get their own campus to go organic, and they’ve been able to bounce ideas back and forth. It’s interesting to learn about different avenues for research and intersections in fields in the environmental sector, he said.
"My favorite part of research is the communication aspect, because you learn a lot more when you get different perspectives looking upon your research,” Inaganti said. “Our research will be able to be applied to other colleges and students who want an organic transition will be able to show our research to administration and show there is backing to going organic.”
The group is far from finished, especially now that the project has been expanded to include all of the University City Campus. They recently won financial backing from and will use it to incorporate new research measures and improve the measures they’re already taking.
“Now that Drexel has gone organic on the entire campus, we're going to be focusing on advocating for the city enforcement of the HOPS law and community engagement, like reaching out to other local institutions in the city and state to let residents know what going organic means for their recreational spaces,” Gao said. “We’ll also be continuing our research, of course, because it can inform organic transitions for other schools, and we’ll be keeping tabs on how the transition is going.”