The 2016 University of Maryland study, "School Gardens in the City" by Rashawn Ray et. al. explores the quantitative impact of Washington, DC's funding for school gardens on academic performance. The study provides a sweeping review of the sociological conditions that impact academic performance, with reference to John Dewey and his support for school gardens over 100 years ago. A few excerpts are provided here:
"John Dewey believed that improving the social and physical environment would lead to better education opportunities....Schools like the Harlem Children Zone, which takes a holistic approach to learning by focusing on aspects inside and outside of the school walls, show the importance of tackling the social and physical environment around schools. Dewey specifically highlighted school gardens as physical and social environments to improve learning."
"Scholars have found that learning in school gardens positively influences academic achievement...as well as nutritional habits....and exercise habits....Our study examines how the Washington, DC School Garden Program serves as a potential gateway to reducing the achievement gap. We ask: Is the presence of a school garden in a school positively associated with student test scores in math, reading, and science?...." (page 380-381).
"Galston (2001) compares traditional classroom-based civic education to service learning. Service learning combines community-based learning with classroom experiences. More recently, scholars have noted the broader benefits of informal learning environments. Learning experiences in these informal contexts [like a school garden] are characterized as learner-motivated, interest-based, voluntary, open-ended, non-evaluative, and collaborative...."
"Moreover, students who have engaged in informal learning settings are more likely to view themselves as scientists as a result of participating in informal learning environments...A report from the National Academy of Sciences notes that experiences in informal settings can improve science-learning outcomes for groups that are historically underrepresented....As a result, major national organizations have shown support for informal science learning opportunities as a means to improving science literacy and addressing serious environmental issues (American Association for the Advancement of Science 1993; National Research Council 1996)."
"School gardens are increasingly becoming a common place for informal learning....In Schools of Tomorrow, Dewey and his daughter detailed several experimental schools that incorporated active learning through nature study and working school gardens....They concluded that school gardens incorporated the best practice pedagogy into instructional practice through participation in real-life activities...."
"Currently, over 3,000 school gardens are being used across the United States for educational purposes (National Gardening Association 2010). These so-called “garden-based learning” programs are found to have numerous positive effects on students. Academically, studies note that garden-based curricula improve the academic achievement of students....A recent synthesis of garden based learning research showed positive impacts on direct academic outcomes with the highest positive impact on science, followed by math and language arts..." (page 384)
"In her study of second graders, Carley Fisher-Maltese (2013) found that a garden-based science curriculum focused on insects resulted in a number of affordances, including notable improvements in science learning, cross-curricular lessons in an authentic setting, a sense of school community, positive shifts in attitude toward nature, and increased collaborative work among students....."
"As school gardens gain popularity across the U.S., understanding their potential impacts becomes increasingly important. Given the lack of cultural and social capital in lower-income communities, exposure to school gardens could result in larger payoffs related to academic achievement, environmental attitudes, and nutrition knowledge for students in these schools." (page 385)
"[The authors conclude:] Students who attend schools with gardens are more likely to perform at the proficient or advanced levels on standardized tests....A central part of our analysis was determining whether there is a significant and positive association between the presence of school gardens in schools and test scores. For math, reading, and science test scores, we found support for this proposition." (page 391-392)