Table 3 Summary of included qualitative studies (n = 16)

Ahmed (2011) [40]

USA

Administrators (n = 2), teachers (n = 4) and garden staff (n = 3) at one rural middle school; school population 50 % Native Hawaiian; low socio-economic status

To examine perceptions of educators about the effects of school-based gardens on children's health and obesity

Snowball sampling starting with the school principle and garden leader

School garden program founded to prevent nutrition-related illness (with community involvement)

Semi structured interviews (4 years after garden established)

Grounded Theory approach using descriptive, open coding; list of themes used to develop a conceptual model

Alexander (1995) [41]

USA

Students (n = 52), teachers (n = 5), parents (n = 3), principal and Master Gardener at one inner city elementary school; students 70 % Hispanic; many from single parent homes

To identify the effects on school children participating in classroom gardens

NR

Master Gardeners’ Classroom Garden Project

Interviews (individual and group) and observation

Constant comparative method; multiple sources of data evaluated for emerging themes

Anderson (2011) [42]

USA

Students (n = 14) at one rural high school

To determine the impact of hydroponically grown vegetables

on obesity indices

Purposely selected students twice during the two-year project

Hydroponic gardening system

Focus groups (n = 7 at each time point i.e. twice during the two-year project)

Block (2012)^a [24]

Australia

Six program schools and six comparison schools; all primary

At program schools only: classroom teachers (n = 26), volunteers (n = 17), other parents (n = 20), children (n = 124), kitchen and garden specialist staff (n = 10)

At all participating program and comparison schools: school principals (n = 12)

To explore participants' expectations and experiences of the program, changes in the school and home environment, highlights and areas for potential improvement

Convenience sampling (all adults invited to participate) and purposive sampling (teachers selected children with range of ages and program experience)

Stephanie Alexander Kitchen Garden Program

Focus groups, individual interviews, participant observation, field notes and researcher reflections (at various time points before, during and after the program)

Inductive thematic content analysis to identify emerging themes and patterns, which were then further analysed according to their relationship with the existing evidence base and theoretical perspectives

Block (2009)^a [25]

Gibbs (2013)^a [26]

To evaluate the achievement of the program in increasing child appreciation of diverse, healthy food

Townsend (2014) [43]

To explore motivations for and impacts of volunteering with the gardening program

Bowker (2007) [44]

UK

Two classes from one primary school and one secondary school; 7–14 years

To gain an

understanding of what the children themselves think about school gardening

Quota sampling to identify two schools; within each school a class unit was selected to further refine the sample; 12 children in each class were randomly selected for interviews

Gardens for Life (to support and extend learning in other curriculum areas)

Concept maps (n = 72) supported by contextual observation, semi-structured interviews (n = 24) (after 6 months) and children’s drawings

Interpretive approach - broad concepts were identified and organised into categories; concept grids and depth scores used to look for patterns

Chawla (2014) [11]

USA

Students (n = 52), teachers and school principals from four high schools; students 14–19 years; 60 % girls; European-American (n = 29); Hispanic (n = 19); Asian (n = 3); Pacific Islander (n = 1)

Research questions: How do students experience natural areas on their school grounds? What values do students find in these natural areas?

Purposive sampling to span the high school age range

Four different gardening programs at four high schools: gardening as school service (elected); agricultural biology class (elected); horticultural science class for teen mothers (required); after school and summer gardening program (voluntary)

Ethnographic observations recorded through field notes, video or photography, and open-ended, semi-structured interviews

Data was repeatedly reviewed with attention to repetitive refrains, recurring patterns and resonant metaphors; triangulation of methods to identify similar themes and discordant data

Chiumento (2012) [12]

UK

Students (n = 36) with signs of Behavioural, Emotional & Social Difficulties (BESD) from two primary and one secondary schools; 10–15 years; 61 % boys; mix of nationalities and ethnicities including children seeking asylum; deprived ward in Liverpool

NR

Students were referred by schools, providing pen profiles of current difficulties including potential behavioural risk factors

Haven of Greenspace (social and therapeutic horticulture); pupil led sessions using NFER five ways to well-being framework (monthly for 6 months)

Draw and write journals (children); closing semi-structured interviews (link teachers); reflective process diary by group therapists

Thematic analysis of interview transcripts; random selection of journals analysed with quality checks

Cutter-Macenzie (2009) [45]

Australia

Students (n = ?) from one city primary school; 6–12 years; all students participating in program (n = 70) had English as a second language and some were recent migrants

To assess the impact of the program against its objectives which included helping to develop strong local communities and school communities; and fostering healthy eating habits

NR

Multicultural school gardens program created to enable disadvantaged schools to establish a culturally focused gardening program (2 years)

Children as researchers including journals, photographs and peer interviews (n = 10); researcher’s field visits, observations and interviews with children and teachers (after 3 months)

Hazzard (2011) [46]

USA

Administrators, teachers, parent and community volunteers and garden coordinators (n = ?) from 10 schools (elementary, middle and high schools)

To ascertain and report best practices for schools implementing or sustaining instructional school gardens

Stratified random sampling from list of all schools with exemplary instructional school gardens programs; principals selected individuals directly involved with the success of the gardens

California Instructional School Garden Program (CISGP)

Interviews with key members

Constant comparative analysis; results used to create best practice models

for schools in California and across the United States

Henryks (2011) [47]

Australia

Parents of children enrolled at the school (n = 5) and another member of the wider community (n = 1) at one primary school

To explore the role played by the school kitchen garden in the lives of its associated volunteers

Purposive sampling by email invitation to volunteers

Stephanie Alexander Kitchen Garden Program

In-depth interviews

Thematic analysis used to build a conceptual map of the experiences of the school kitchen garden volunteers, including the motivations, benefits and challenges that volunteers experienced; combination of inductive and deductive approaches

Lakin (2008) [48]

UK

Head teacher, a governor, a teacher and groups of children in Year 3 (n = 5) and Year 6 (n = 5) at one semi-rural primary school; 7–11 years

NR

School B selected to represent example of good practice; children selected by the head teacher for their involvement in the innovations

Health Promoting Schools: Gloucestershire Food Strategy

Detailed interviews; observations; classroom display and classroom activities as exemplified by the children's workbooks (over 3 days of visits)

Miller (2007) [49]

USA

Teachers (n = 19) and children (n = ?) from one early education setting: Dimensions Educational Research Foundation; 3–6 years

To examine the skills young children are developing when they are engaged

in developmentally appropriate activities in the greenhouse and garden

NR

Dimensions outdoor classroom including garden and greenhouse areas (two small group activities a month)

Teachers’ documentation (nature notes) of children interacting with nature in the garden/greenhouse; children’s drawings and work from their garden/greenhouse experiences (n = ?); focus group interviews conducted with teachers (n = 19) on three occasions over two years.

Teachers’ nature notes and children’s work were analysed using a systematic framework from prior data analysis of teachers’ visual notes; key themes identified from focus groups

Ming Wei (2012) [13]

USA

Students (n = 20), teachers (n = 9), school principal, school counsellor, student services coordinator and parents/caregivers (n = 4) from one rural elementary school; students 55 % girls; from low to middle income families; native culture

To better understand the experience of student learning in the context of school garden-based education and to determine the relevance of school gardens as a site for learning making

Convenience sample of third, fourth and fifth grade Gifted and Talented students who spent two or more hours in the garden each week

The Discovery Garden: using an interdisciplinary standards-based school garden curriculum

Formal interviews and talk story (informal chats); field notes collected during the garden classes and garden-based activities (over one semester)

Listened and looked for recurring patterns; constructed of a network of related and connected themes; content analysis using constant comparative methods

Passy (2010) [50]

UK

Two samples (two stages) from 10 primary schools e.g. stage 1: senior leaders (n = 11), garden leads (n = 10), other members of teaching staff (n = 10), teaching assistants (n = 2), parent governors (n = 2), other parents (n = 2) and pupils (n = 43)

To assess the impact that using a school garden had on primary pupils’ learning, behaviour and health and wellbeing

Stratified random sampling from list of participating schools; weighted towards those with higher levels of benchmark achievement

Campaign for School Gardening (Royal Horticultural Society)

Case studies including interviews and observations (two stages over six months); schools were given disposable cameras and diaries in which to record activities

Somerset (2005) [51]

Australia

Teachers responsible for vegetable gardens at 12 primary schools

To investigate the nature and extent of the use of school gardens in a defined region of eastern Australia

All schools with vegetable gardens (outdoor or greenhouse) as identified by telephone survey

Schools with vegetable gardens (no one intervention)

Open ended questionnaire; face-to-face interviews

Data were then categorised thematically and analysed

Viola (2006) [52]

Australia

Key informants from one primary school (n = 6) and one secondary school (n = 9); students in grades 4–9; Indigenous Australians; remote rural communities

To examine how effective school gardens are as a nutritional education tool in Indigenous Australian school settings

Schools selected by researcher; participating grades determined by school principals; key informants selected from each community advisory group

Outreach School Garden Project (incorporated formal nutrition and gardening education lessons into the core school curriculum

Semi-structured interviews; reflective journal; event log (over six months with outreach visits for 3–5 days every 6–8 weeks)

Descriptive qualitative approach; triangulation of research methods and data sources