A systematic review of the health and well-being impacts of school gardening: synthesis of quantitative and qualitative evidence

Abstract

BackgroundSchool gardening programmes are increasingly popular, with suggested benefits including healthier eating and increased physical activity. Our objectives were to understand the health and well-being impacts of school gardens and the factors that help or hinder their success.MethodsWe conducted a systematic review of quantitative and qualitative evidence (PROSPERO CRD42014007181). We searched multiple databases and used a range of supplementary approaches. Studies about school gardens were included if they reported on physical or mental health or well-being. Quantitative studies had to include a comparison group. Studies were quality appraised using appropriate tools. Findings were narratively synthesised and the qualitative evidence used to produce a conceptual framework to illustrate how benefits might be accrued.ResultsEvidence from 40 articles (21 quantitative studies; 16 qualitative studies; 3 mixed methods studies) was included. Generally the quantitative research was poor. Evidence for changes in fruit and vegetable intake was limited and based on self-report. The qualitative research was better quality and ascribed a range of health and well-being impacts to school gardens, with some idealistic expectations for their impact in the long term. Groups of pupils who do not excel in classroom activities were thought to particularly benefit. Lack of funding and over reliance on volunteers were thought to threaten success, while involvement with local communities and integration of gardening activities into the school curriculum were thought to support success.ConclusionMore robust quantitative research is needed to convincingly support the qualitative evidence suggesting wide ranging benefits from school gardens.

Impact of school gardens in Nepal: a cluster randomised controlled trial

“…Second, half of the children in the control group in year 1 switched to the treatment group in year 2, which eliminated most of the selection bias observed in year 1 while the significance levels of the estimated impact remained the same. We note that none of the 18 quantitative impact studies reviewed by Ohly et al (2016) did such a repeated experiment. Third, we controlled for several confounding factors by including them as additional covariates in the regression analysis.…”

“…This is the first such application to our knowledge. Recent reviews of impact studies on school garden interventions in high-income countries concluded that most studies suffered from selection bias, lack of control of confounding factors, high sample attrition and low sample sizes (Ohly et al 2016;Langellotto and Gupta 2012). Our study does not have many of these shortcomings: The rate of sample attrition was very low, we controlled for several confounding factors, and our sample of children and schools was much larger than used in most previous studies.…”

“…The impact of school garden interventions is the result of a complex interaction between schoolchildren, teachers, parents, project team members and other community members. In their review, Ohly et al (2016) found that only 2 out of 40 school garden studies generated quantitative and qualitative evidence for the same intervention. We attest to the importance of using a mixed methods approach in future studies on school gardens.…”

“…However compelling the concept, the evidence base for the impact of school gardens remains small (Ozer 2007;Blair 2009;Robinson-O'Brien, Story, and Heim 2009;Ohly et al 2016). Previous studies have relied on small samples of schools from which it is difficult to generalise (Langellotto and Gupta 2012).…”

“…Previous studies have relied on small samples of schools from which it is difficult to generalise (Langellotto and Gupta 2012). A recent review of quantitative studies rated 14 out of 18 studies as weak in scientific rigour (Ohly et al 2016). This was mostly because of selection bias, lack of control for confounders, and high levels of sample attrition between baseline and follow-up.…”