The Healthy Gardens, Healthy Youth (HGHY) study examined the effects of school gardens on children’s fruit and vegetable (FV) consumption, FV preferences, knowledge of nutritional and plant science; and STEM self-efficacy. This study targeted schools that did not already have gardens and had at least 50% of students qualifying for free or reduced price meals. During the grant enrollment phase, 80 schools in Arkansas, Iowa, New York, and Washington were screened for eligibility. Ultimately, 60 of those schools met inclusion criteria and a total of 47 schools participated in this study. The participants in this study were children in grades 2, 4 and 5 (ages 6-12 years) at the start of the study, and were followed into grades 3, 5 and 6 respectively over the 18 months of data collection.
Research Design & Timeline
In this longitudinal, randomized controlled trial, schools within each state and region (rural, suburban or urban areas) were randomly assigned to receive the intervention or to serve on the waitlist control group. Baseline data were collected in Fall 2011 followed by garden implementation (Spring 2012) and three waves of follow-up data collection (late Spring 2012, Fall 2012, late Spring 2013). Waitlist control schools received gardens and access to the Educational Toolkit following the final data collection period (late Spring 2013).
The Garden Intervention
Each class in the intervention group received a raised bed or container garden kit; access to the Educational Toolkit consisting of lessons, activities, suggested recipes, and a garden implementation guide; and on-line training on how to use the toolkit. Lessons were delivered by a Cooperative Extension educator or the classroom teacher. In some cases, trained volunteers (e.g. Master Gardeners from the local Cooperative Extension office) provided additional assistance. Classrooms in the wait list control group received a garden kit and access to the Educational Toolkit once data collection was completed in Spring 2013.
Current results, publications, and research briefs summarizing findings can be found on Dr. Nancy Wells’ research page. Dr Wells served as the Research Director for the project, overseeing research design, data collection and analysis, and interpretation of results.
Over the course of the two-year study, children in the garden intervention group increased the amount fruit (grams) that they consumed during lunch at school, while children in the control group maintained virtually the same level of fruit consumption. In addition, the study examined what percentage of foods on the lunch tray were consumed by the children. Results indicated that children in the garden intervention increased the percentage of both fruit and low-fat vegetables that they consumed while children in the control group ate a slightly lesser percentage of both the fruit served and the low-fat vegetables served at the end of the study, compared to the beginning.
Overall, the school gardens did not have a statistically significant influence on children’s fruit & vegetable preference nor on availability or consumption at home. However the robustness of the garden intervention – ie. gardening activities and lessons — did predict increases in availability of fruits & vegetables at home. The number of nutrition lessons and gardening activities that the children received (the fidelity of the intervention) positively predicted an increase in fruit & vegetable availability at home. In other words, the greater exposure to nutrition and gardening, the higher increases in fruit availability, vegetable availability, and low-fat vegetable availability, in the children’s home environment.
The school garden intervention had a significant effect on children’s science knowledge (nutrition and plant science) over the two-year period. In other words, children in the school garden intervention group showed a greater (though modest) increase in science knowledge than children in the wait-list control group, who received gardens at the end of the study. Moreover, the robustness, or “fidelity” of the garden intervention corresponded with science learning such that children with a weak intervention learned the least and those who experienced a “very robust” intervention increased science knowledge the most. This finding is published in the International Journal of Science Education.
Nancy M. Wells, Ph.D.
Nancy earned a joint PhD in Psychology and Architecture from the University of Michigan and completed an NIMH post doc in the School of Social Ecology at the University of California, Irvine before joining the Cornell faculty in 2001. As an environmental psychologist, Dr. Wells studies the effects of the built and natural environment on human health and health behaviors. She can be reached at: firstname.lastname@example.org