Identifying Key Benefits and Characteristics of Community Gardening for Vulnerable Populations: A Systematic Review

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Introduction
Te present study seeks to identify the benefts of community gardening for vulnerable populations reported in the literature and determine if there are specifc program characteristics associated with such benefts.Community gardening is operationalised as a form of gardening that "requires individuals to converge to share space, resources, food, and knowledge in a collective and cooperative way" [1]: p. 3).
Evidence highlights a growing interest in the exploration of health, social, and economic inequalities globally and within countries themselves [2].Ostensibly, this is due to initiatives such as the World Health Organization's 2005 Commission on Social Determinants of Health and Fair Society, Healthy Lives [3], which are predominantly focused on high-income countries.No matter the location, Wilkinson and Pickett's [4] extensive global research shows that the more extreme these economic inequalities are within countries themselves, the poorer overall the health and social outcomes will be within society.Te recent COVID-19 pandemic highlighted and fuelled these disparities with examples including virus-related infections and mortality and reduced access to healthcare services such as mental health support [5,6].
Te intersection between these inequalities and vulnerable communities is apparent with the most at-risk populations facing the brunt of negative health, economic, and social outcomes.Te research team defnes vulnerable peoples and populations by applying World Health Organization classifcations and is inclusive of terms such as disadvantaged and marginalised groups [7].We recognise that certain segments of the population are more afected by health inequalities including groups such as those who are homeless [8,9], youth refugees [10], social housing residents [11,12], and Indigenous populations [13].In the Australian context (where the authors of this paper are located), there are a range of varying determinants of health, which are unique to the geographical location including rural and remote communities [14] and population groups, for example, Aboriginal and Torres Strait Islander peoples [15].
Te United Nations has created frameworks to operationalise concepts and objectives to reduce health, social, and economic inequalities.Te Millennium Development Goals (MDGs) established in 2000 drove genuine progress across a range of economic and social development indicators and have been succeeded by the Sustainable Development Goals (SDGs).For the frst time, these provide specifc targets and indicators across the 17 aspirational areas of sustainable development.Health inequalities, sustainability, and equity have been emphasised by leaders as former United Nations Secretary General Ban Ki-Moon, for example, highlighted that the SDGs seek to "leave no one behind" [16]: 54).Nonetheless, there still remains a major gap to address with vulnerable communities still facing major inequalities.Tis paper seeks to systematically explore the evidence available around community gardens as an initiative to improve health outcomes for the most vulnerable in our society.
Evidence-based research highlights the importance of green spaces on people's health outcomes [17].During the COVID-19 pandemic, research highlighted a negative correlation between green neighbourhoods and higher COVID-19 rates [18] with subsequent calls to enhance access to green spaces as a solution to reduce health inequalities exacerbated by COVID-19 [19].Engaging in green spaces is shown to be a protective measure against poor cardiovascular health, diabetes, obesity, and hypertension which are causally linked as risk factors for COVID-19 [20].In addition, with exposure to green spaces boosting physical and mental health, closure of these spaces during COVID-19 impacted vulnerable populations more than others [20].
Te impact on health, however, transcends mortality rates with green space and the destruction of nature impacting people's mental, social, and emotional wellbeing [21][22][23].Gardening is one of the most popular leisure time activities to connect with these green spaces [24] and has experienced a burgeoning interest during COVID-19 [25][26][27].Evidence around gardening shows the clear health, wellbeing, and social benefts of this activity [28][29][30][31].
Recent academic evidence highlights the public health, social capital/cohesion, and economic benefts of community gardening [32][33][34][35][36][37].Some specifc community garden benefts include increasing social capital [1], mental wellbeing, and life satisfaction [38].A recent scoping review by Howarth et al. [28] identifed the positive impact on health and wellbeing as a result of participation in gardening.Although benefcial to direct healthcare strategies, the span of the scoping review means that further comprehensive review of the literature to inform policy and practice would be valuable.
First, there is a need to focus specifcally on vulnerable populations as they are in most dire need of evidence-based and efective healthcare strategies.Second, with burgeoning resources being invested into community gardening for vulnerable populations (e.g., Botanic Gardens around the world seek a new social role), Brooklyn's Botanic Gardens in the USA since 1993 and the Royal Botanic Gardens in Sydney since 2000 have developed outreach programs that support vulnerable communities to community garden [39,40] and studies demonstrating benefts for vulnerable populations such as refugees' communities (e.g., [41,42]), and it is paramount to understand and capitalise on this literature as it pertains specifcally to community gardening for the beneft of communities.Finally, an open-ended review where the types of outcomes are not limited within the inclusion and exclusion criteria will produce a comprehensive understanding of documented outcomes more so than achieved in current reviews such as by Howarth et al. [28], where only limited outcomes have been considered.
Recent systematic literature reviews published in the English language indicate the benefts of gardening and community gardening to health, wellbeing, and social outcomes [28,29,[43][44][45].However, except for one review [46], there is a lack of information on how these benefts translate for marginalised and vulnerable communities.Te present study will address this gap by systematically identifying the benefts of community gardening for vulnerable populations.Te secondary aim of this study is to examine if there are specifc program characteristics associated with such a change and "thereby provide a solid basis for policymakers and practitioners to work more efectively to address health and social inequities" [7]: p. 2).

Materials and Methods
A systematic review was the method chosen for this study because, to date, no such review of peer-reviewed academic literature published in the English language has been undertaken to explore this topic.Te protocol for the systematic review is available in a study by Tracey et al. [7].

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Health & Social Care in the Community  [47] were used to describe the eligibility criterion for this review (see Table 1).In addition, the inclusion and exclusion criteria are described in detail below.
2.1.1.Inclusion Criteria.Tis systematic review included peer-reviewed articles, published in the English language, which explored either impact or outcomes of community garden participation between 1985 and 2022.Te authorship team classifed this activity as either needing to be undertaken in a community setting or population focused or having a social aspect to it.Both qualitative and quantitative study designs have been included in this review.Specifed medical subject headings (MeSH) terms and keywords were prepared by the investigators to ensure comprehensiveness.Te search terms were pretested in the CINAHL database and adapted to all other databases (see Supplementary Appendix 1).Furthermore, only papers that had an emphasis on vulnerable populations were included (keywords such as marginalised and disadvantaged were included in search terms).Tese populations include, for example, refugees, social housing residents, people of low socioeconomic status (SES), Indigenous peoples, people who are homeless, those unemployed, and people with disabilities.

Exclusion Criteria.
Studies that focused on a population with a specifc health condition (for example, lung or skin cancer) were excluded from the systematic literature review because this study is focused on vulnerable populations and not those with specifc medical conditions.Only peer-reviewed quantitative and qualitative research studies published in the English language were included.Tus, case reports, case series, letter to editors, and systematic and literature reviews were excluded.

Data Extraction and Analysis.
Te search results were screened initially (both titles and abstracts) by one author (N.M).After this, three authors (D.T; A.B; T.G) independently reviewed potentially relevant abstracts and titles to include and exclude articles.Following the initial screening process, all articles were assessed by two authors independently to deem if they were appropriate to include in the systematic review analysis.When there was a disagreement between these authors, we had a group discussion to resolve this issue, and if it was unable to be resolved, a third author reviewed papers in question.Tirteen academic search engines were utilised, and articles were put onto EndNote to document the systematic review process (Figure 1: Prisma).Te following databases were used to collect this information: (1) PubMed, (2) Medline, (3) Scopus, (4) ScienceDirect, (5) Cumulative Index to Nursing and Allied Health Literature (CINAHL), (6) PsycINFO, (7) Web of Science, (8) Academic Search Complete, (9) Education Source, (10) Education Resources Information Center (ERIC), (11) Psychology and Behavioral Science Collection, (12) SocINDEX, and (13) Allied Health and Complementary Medicine Database (AMED).Te keywords of the search examined outcomes related to community gardening (including allotment gardening).Search strings also included words related to vulnerability (for further information, please see the previously published study by [7].
Te initial screening process removed all duplicates, articles not in English, and other studies identifed as clearly unsuitable for inclusion, for example, due to a lack of focus on community gardening.Te extracted data included authors, setting/country, year of publication, sample, study type, intervention characteristics, and outcomes measured.Figure 1 presents the PRISMA fow diagram.
Tis study involved a narrative synthesis of the literature.Te narrative synthesis assessed the outcomes measured and the key fndings across each outcome.Tese fndings were evaluated against study type and intervention characteristics.Table 2 presents the results of the present review.

Critical Appraisal Tool. Te Critical Appraisal Skills
Program (CASP) checklist [78] was used to assess the methodological quality of both qualitative and quantitative studies.Te CASP checklist was selected as it has diferent checklists (examining the study validity, risk of bias in recruitment, exposure, outcome, confounding factors, reporting of results, and acceptability of fndings) to assess the quality of diferent research designs.Hence, this tool ensured that all studies included in this review were assessed for their design and to highlight any biases.For every study, each criterion within the CASP checklist was given a score of 1 for being "met" and 0 for being either "unmet" or "can't tell."Tese individual scores were summed to give an overall score for the respective study (see Supplementary Appendices 2 and 3).Tree authors (N.M, J.K, and A.B) independently applied the appropriate checklist to the included studies, and disagreements (if any) were resolved by a third author (D.T).

Study Selection.
Initially, a total of 13,959 studies were identifed following the outlined search strategy from all selected electronic databases and manual search.Duplicates were removed, and a total of 11,200 titles and abstracts were identifed for further reading.Of these, 307 studies were selected for full-text reading, and fnally, 29 studies were included in this review (see Figure 1).An updated literature search was conducted in late 2022, and four more studies that matched the inclusion criteria were subsequently included in the narrative review (see Figure 1).).However, some of the studies had an overlap in terms of their specifed research design.

Study and Participant Characteristics.
Of the total 33 studies, only two studies used a comparator design, that is, gardeners vs. nongardeners [56,64].One study included only program coordinators as participants [49], while two studies included both gardeners and garden managers/organisers [52,75].Only one study had a preintervention and postintervention without a control group and had a mixed-method study design [58].
Te total number of participants (including males and females) were 1,674, ranging from fve to 520 participants.Of these, 1,556 were gardeners, 25 were program coordinators or garden managers, and 93 were nongardeners.In terms of age, participants ranged from fve to 89.5 years of age.In terms of gender, based on the studies which had clearly specifed the gender of the participants, 504 were women and 153 were men out of the total participants.As for the nature of vulnerability, most studies had participants with overlapping vulnerabilities.Twenty studies included participants categorised to be of low socioeconomic status Health & Social Care in the Community     Health & Social Care in the Community (SES) or socioeconomically disadvantaged.Fifteen studies included participants from various ethnically and culturally diverse backgrounds ranging from Africa, Asia, South America, the Middle East, and Russia.One study [67] included only Aboriginal participants in Canada, while one study [54] included a mix of participants from First Nation and minority groups in Canada.One study [75] included persons with physical disabilities.Seven studies included refugees and asylum seekers from culturally diverse backgrounds, while two studies solely included homeless women.Tree studies primarily included African American participants with low SES.Lastly, four studies included older participants and/or participants with disability from multicultural and low socioeconomic-status backgrounds.

Critical Appraisal.
Te CASP quantitative study appraisal scores varied, though two [50,64] out of the total fve studies scored ten from a possible CASP score of 12. Due to limited quantitative analysis within the studies, most of the studies could not score perfectly (see Supplementary Appendix 2 for CASP appraisal scores).All the studies had a clearly focused question, and the results were considered reliable.Most studies scored poorly on the identifcation of important confounding factors and precision of results.
Te CASP qualitative study appraisal scores also varied, though eleven studies [41,57,58,60,62,66,67,71] out of a total of twenty-eight studies scored eight or more from a possible CASP score of 10.Only one study took into consideration the infuence of the researcher and participant relationship on the study outcomes (see Supplementary Appendix 3 for CASP appraisal scores).All included studies had clear aims and used appropriate methodologies except one study [65] which did not provide any description of the data collection method, sample selection and recruitment, and analytical methods used.Most studies did not adequately report how they addressed ethical issues such as informed consent in recruitment, which also restricted their CASP scores.
Besides undertaking the critical appraisal of the included studies using the CASP tool, the investigators identifed an important limitation in ffteen included studies [41, 49, 52-56, 60, 65, 68-70, 72, 74, 76].Tese 15 studies did not report on receiving ethical approval to conduct their respective study despite some of these studies involving young children.

Identifed Benefts of Community Gardening for Vulnerable Populations.
Every study, except the one by Shisanya and Hendriks [70], found wide-ranging positive benefts of community gardening among vulnerable target groups, while Shisanya and Hendriks [70] reported improved food safety as the sole beneft of community gardening.Te reported results in terms of benefts of community gardening were grouped into the following categories (described in order with most prevalent beneft frst): "social connection," "health," "education," "nutrition," "cost benefts," "cultural awareness and/or connection," "connection to the nature," "food safety," and "area development and safety" (see Table 2).Only one study [70] conveyed no benefcial outcome following participation in community gardening.Tis study established no improvement in food security among low-income households from community gardening.Furthermore, one study [75] reported community gardens serving as a source of employment for some participants but also identifed accessibility and participation constraints (due to participants' physical disabilities) along with undesirable social cohesion with the garden managers.
(1) Studies Reporting Outcomes on Social Connection Benefts.Te majority of studies (n � 29) [12, 41, 42, 48-57, 59-64, 67-69, 71-77] reported a positive infuence of community gardening towards developing social connections with families, neighbours, and fellow gardeners.For example, Gerber et al. [56] examined various dimensions of social support based on the "Medical Outcomes Study Social Support Survey" (MOSS SSS) [79].Compared to nongardeners, gardeners articulated greater social support (with moderate to large efect size), tangible social support (with a large efect size), emotional/informational social support (with a medium efect size), and positive social interaction (with a large efect size), respectively.Furthermore, Bussell et al. [51] discovered 50% of the participating gardeners recounted better community connection and 61% developed new friendships during the program.Additional outcomes reported across the abovementioned studies were a medium to meet and interact with family and friends, build relationships, experience feelings of community, improved community cohesion, ability to resolve disputes, develop a social support system within community, and an inclusive space for a diverse range of people.
(2) Studies Reporting Outcomes on Health Benefts.Twentytwo studies described outcomes on health benefts of participants engaged in community gardening.Te studies reporting on this dimension addressed several outcomes: an improvement in both mental and physical health [49, 51-53, 56, 57, 59-61, 64, 66, 71, 76, 77], only mental health gains [48,50,54,62,68,73,75], and fnally physical health improvements [74].Based on the quantitative research design, the study by Armstrong [49] reported 75% of participants had an enhancement of their mental health and 70% had an improvement in their physical health following their participation in community gardening.Bussell et al. [51] found after participation in gardening, 65% of the gardeners felt mentally relaxed and 58% felt advancement in their overall health.Strout et al. [71] reported participation in gardens led to a 10% positive diference in participants' distress and cognitive health based on the Mini-Mental State Examination (MMSE) assessment tool [80].In relation to qualitative studies, all studies displayed varying health benefts from gardening ranging from participants feeling relief, happiness, alleviation of mood, psychological boost, improvement in depression, avenue for exercise, stretching, and physical activity.
In terms of benefts in life skills, Armstrong [49] discovered 51% of participants stated gardening improved their attitudes about their neighbourhood and 33% felt that gardening played a role in addressing neighbourhood issues.Booth et al. [50] observed statistically signifcant diferences (F � 3.18, p � 0.045) in individual empowerment among three participant groups, regular gardeners, occasional gardeners, and nonparticipants.Other reported life skills acquired through community gardening were gardeners serving as a relational teacher in terms of how an individual should live, share, and care for others [54].Also, gardeners identifed improved communication, empowerment, autonomy, self-efcacy, sensory awareness, mindfulness, and leadership skills [56,57,59,67,72,76,77].
In terms of benefts in gardening knowledge, Grier et al. [58] showed a signifcant improvement in preinterventional and postinterventional gardening knowledge (efect size � 0.33, p � 0.01).Other studies reported gaining knowledge and skills of gardening, learning about economic benefts of harvested foods as outputs for income means, and increased knowledge of fruits, vegetables, and traditional foods [62-64, 66, 69].McArthur et al. [65] explored the impact of gardening projects on academic learning of youth aged 6-13 years during summer 2007, fall 2007, and spring 2008.Te study found that gardening activities positively infuenced children's academic performance.In comparison to public school system grades, the participating youths' grades increased in science, mathematics, language, and reading.Pierce and Seals [68] uncovered a similar positive impact of gardening on life skills and academic performance.
(4) Studies Reporting Outcomes on Nutrition-Related Benefts.Fifteen studies identifed nutritional benefts of community gardening ranging from improved access to healthy foods, increase in availability, and/or intake of healthy foods [48, 50, 55, 56, 58, 51, 60, 62-64, 67, 71, 73, 74, 77].Algert et al. [48] discovered that after harvesting vegetables in their gardens, there was a twofold increase in the vegetable intake of community gardeners (i.e., from 2.0 cups/day to 4.0 cups/ day, 2.0 ± 0.8 additional cups/person/day).Booth et al. [50] compared fruit and vegetable intake between three groups: nonparticipants, occasional participants, and regular participants.Te study found a higher intake of fruit and vegetables among regular and occasional participants in comparison to nonparticipants, with statistically signifcant diferences across the three participant groups in vegetable intake (F � 3.30; p � 0.04).Hartwig and Mason [60] described an increase between the preseason and postseason surveys for the question "do you eat fruits and vegetables throughout the day."Initially, 64% respondents stated that they ate fruit and vegetables throughout the day, and this increased to 78% by the end of the season.Bussell et al. [51] conveyed that 90% of participants felt that not only had their household diet improved, but they had also eaten more fresh fruit and vegetables since they started to grow their own produce.Some studies uncovered that many community gardeners reported that their produce was of higher quality, organic, and tasted much better than store-brought produce [48,60,77].Some other nutritional benefts identifed were that community gardening enabled gardeners and their households to learn to eat healthy foods, develop food skills, eat new foods, and/or eat more fruit and vegetables, respectively [55,63,67,74].In contrast, one study [70] found community gardening had no impact on participants' food intake, with 72% of participating households reporting that they still consumed poor-quality food.
(5) Studies Reporting Outcomes on Cost Benefts.Nine studies reported fnancial benefts and/or cost savings because of community gardening [48,49,51,52,60,62,64,74,75,77].Tis aspect is important considering its potential signifcance in low-income communities.In terms of cost savings, participants in diferent studies disclosed their estimated savings were from as low as $25 to as high as $84 in a month or season [48,51,60].Hartwig and Mason [60] interviewed immigrants and refugees from Asia and sub-Saharan Africa based in the USA and reported that 92% of participants stated they spent less money on food and that the majority (61%) shared that they saved around $25 during the gardening season.A study by Bussell et al. [51] also found signifcant cost savings from gardening among low-income, ethnically diverse groups based in the USA.For instance, 78% participants reported savings in their grocery bills, ranging from <$39 to $60.Some (12.5%) participants, besides self-consuming the produce, sold some of their produce to buyers, hence gaining income from it.Similarly, using produce from gardening as an income supplement was conveyed by 10% of gardeners in a study by Armstrong [49].
(6) Studies Reporting Outcomes on Cultural Awareness and/ or Connection Benefts.Six studies reported a positive infuence of community gardening on raising cultural awareness and/or developing cultural connection among gardeners [42,52,54,56,64,72].For instance, Datta [54] implemented cross-cultural gardening activities for gardeners from First Nations and minority groups from Canada and reported the development of decolonisation and reconciliation skills among participants.Te activities allowed participants to directly engage with their First Nation elders and story holders and hear stories of colonisation in their region to get an understanding of it.Furthermore, other studies (e.g., [42,52,56]) found gardening provided participants an opportunity to connect with their own cultural roots and also develop an understanding of other cultures.Participants from Bhutan and Nepal, for example, often discussed memories and exchanged stories from their home counties [56].(7) Studies Reporting Outcomes on Connection to Nature Benefts.Seven studies reported a positive impact of community gardening on establishing a connection with nature [12,49,52,53,59,62].All of these studies highlighted that participating in gardening provides a source of contact and relationship with nature and its beauty.In addition, Armstrong [49] stated that 70% of participants felt that gardening allows them to enjoy open space or nature.
(8) Studies Reporting Outcomes on Food Safety Benefts.Tree studies explored the impact of community gardening on food safety [12,70,74] with two studies [70,74] based in South Africa explored the impact of community gardening on food safety.Tembo and Louw [74] conveyed one of the major achievements of their community gardening project was that it enabled gardeners to combat hunger by improving access to food for their households.In contrast, Shisanya and Hendriks [70] reported 89% of households participating in community gardening remained anxious about food supplies, were severely food insecure, and consumed inadequate food based on the Household Food Insecurity Access Scale [81].Te study concluded that community gardens were not able to solve the specifc issue of food insecurity in low-income households based in the rural area of KwaZulu-Natal, South Africa.

(9) Studies Reporting Outcomes on Area Development and
Safety Benefts.Only one study explored the impact of community gardening on area development and neighbourhood safety [49].Participants discovered that community gardens create a sort of neighbourhood watch which helps them look out for each other in the context of a high crime rate area and that a neighbourhood association was also established.Furthermore, following the setup of community gardens, the adjoining area was developed with new sidewalks, tree plantations, landscaping, parks, and playgrounds [49].(10) Studies Reporting Outcomes on Enhanced Employment.Only one study reported the beneft of employment creation through community gardens [75].All study participants had physical disabilities, but they were employed informally at the garden and received monthly stipend based on the sales of the produce.Such arrangements gave the participants a sense of work responsibility and working according to employment codes.

Identifed Characteristics of Community Gardening as an Intervention for Vulnerable Populations.
Twenty-four studies reported limited or no information in terms of how community gardening was used as an intervention for improving the health and wellbeing of vulnerable population groups.Of the remaining nine studies, two studies [50,54] provided limited information on the intervention characteristics, that is, only curriculum related details, while seven studies [57,58,[64][65][66][67]71] provided descriptive information on various components of the intervention categorised as curriculum, length, the number of sessions, duration of each session, the number of participants in each session, and the personnel involved (see Table 2).In terms of curriculum, of the seven studies, only one [58] used a validated curriculum.Grier et al. [58] adapted the community gardening educational material from the Junior Master Gardener curriculum [82] and incorporated nutrition-focused lessons (taken from the US Department of Agriculture's MyPlate website [83] to align it closely with social cognitive theory [84]).Furthermore, the lessons were modifed to create cultural relevance for the participants.Te most cited intervention characteristics were that of personnel involved, the number of sessions delivered, and the length of the sessions.Te reporting of these details, however, was scant, with only 13 out of 29 (45%), 14 out of 29 (48%), and 12 out of 29 (41%) of studies, respectively, providing such details which would facilitate future intervention replication or critique.In relation to the secondary aim of the present review (that is, to evaluate the association between program characteristics and outcomes of community gardening), considering only seven out of the total 29 included studies reported certain program characteristics.Terefore, there is limited information on how program characteristics can infuence a positive change in vulnerable individuals or groups involved in community gardening.

Association between Program Characteristics and
Positive Life Outcomes.As mentioned previously, only seven studies [57,58,[64][65][66][67]71] provided detailed information on the respective program characteristics (see Table 2).However, most of the information related to the program characteristics varied between the studies, thus limiting the understanding of which program characteristics might lead to positive life changes among participants involved in community gardening.Nonetheless, it is suggested that length of the community gardening intervention may potentially infuence positive outcomes among the study participants.For instance, a study by Martin et al. [64] ran the intervention for a period of two-fve years and reported multiple positive outcomes such as improvement in health and wellbeing, educational skills, nutrition, social and cultural connections, and fnancial costs.

Discussion
Tis systematic review is the frst attempt to identify what type of positive changes were experienced by vulnerable participants engaged in community gardening and key program characteristics associated with such a change.Previous reviews published in the English language focused solely on the benefts of community gardening more generally and did not apply to disadvantaged groups specifcally.Collectively, the included studies provide important information on the extensive benefts of community gardening Health & Social Care in the Community for vulnerable populations.Te systematic review, however, identifes limitations in methodological rigor and breadth of intervention description which restricts future replication.
In terms of origin of studies, of the 33 studies, the majority (n � 27) were conducted in high-income countries except for fve studies [62,70,[74][75][76] that were conducted in an upper middle-income country and one study was [73] conducted in a lower middle-income country.Tis may refect the limited scope of employing community gardening to alleviate the health and wellbeing of vulnerable populations based in lower middle-and low-income countries across the globe [85].It may also be the result of the inclusion criteria which specifed that studies must be published in the English language.Furthermore, this review highlights signifcant recent interest in community gardening and its benefts focusing primarily on vulnerable groups since most of the included studies (n � 29) have been published within the last decade.Women were substantially overrepresented in studies compared to men, while the main criteria for vulnerability depicted in the studies included low socioeconomic-status and cultural diversity.
Te included studies suggested that community gardening provides a multitude of positive benefts for vulnerable and marginalised individuals.In order of most to least frequently cited outcomes, community gardening was shown to improve social connection, health, education, nutrition, cost benefts, cultural awareness and/or connection, connection to nature, food safety, area development and safety, and employment.An enhancement of social connection the most prevalent fnding (29 out of 33 studies), followed by health and education (22 out of 33 studies), and nutrition (15 out of 33 studies).
Tese fndings are consistent with the literature that highlights the positive infuence of community gardening on health and wellbeing of the general population [30,[43][44][45] and social and economic benefts [32][33][34][35][36][37].Te systematic review extends current knowledge by focusing specifcally on vulnerable populations and considering outcomes beyond just health and wellbeing unlike other recent reviews, e.g., [28].Here, a relative emphasis on benefts to social connections, education, and nutrition is apparent for vulnerable populations in comparison to reviews considering the general population.Given the widening inequity experienced by vulnerable populations [5,6] comparatively, this new knowledge is timely to infuence community policy and practice.
In relation to the association between specifc characteristics of community gardening programs and positive life outcomes, this review could not clearly identify any specifc program characteristic that would enhance the impact of community gardening on participants' lives.Te probable reasons might be heterogeneity in the study settings, population, and assessment methods; similar fndings have been reported by previous reviews on this topic [30,44,45].Furthermore, most of the studies did not follow any validated or recognised community gardening curriculum with defned parameters.Hence, it was difcult to compare the program characteristics across the included studies.
Te variability in terms of participants, settings, study design, and assessment methods was the likely reason for a high level of heterogeneity among the included studies.Moreover, the quality assessment of most studies was measured to be moderate, which indicates the need for improved methodological rigor in future research.Tese limitations have also been acknowledged in previous reviews [43][44][45]86].In fact, the current review identifed that only two out of the 33 studies employed a comparator and that only one study utilised a pre-postintervention design with no control group.Although the fndings of the systematic review are encouraging, the employed methodologies are unable to attribute positive outcomes specifcally to participants' engagement in community gardening.Furthermore, with 22 studies reporting limited or no information about the community gardening intervention, policymakers and practitioners have reduced capacity to capitalise on the research to replicate program characteristics that have demonstrated positive outcomes for vulnerable populations.

Conclusion
Tis systematic review represents a landmark study as it is the frst to evaluate what outcomes are evidenced for vulnerable populations following their participation in community gardening.Te narrative synthesis of the 33 included studies shows that all studies reported positive outcomes of community gardening for participants, with the most frequently cited benefts being in areas of social connection, health, education, and nutrition.Hence, the review fndings have the capacity to assist policymakers and practitioners to leverage existing benefts of community gardening to better address health and social inequities for vulnerable populations While the fndings are encouraging, the review aim of identifying program characteristics associated with a positive impact was not achieved.More can be done to inform and guide the implementation of community gardening for the beneft of vulnerable communities.Researchers are urged to strengthen evidence available by employing methodologies that utilise comparator groups or pre-post designs and provide practitioners with comprehensive program descriptions to allow the replication of evaluated programs.attainment, and nutritional intake.(2) Studies provide limited information and identifcation of characteristics of community gardening programs limiting the translation of research to practice.(3) Te quality of the methodological designs on this research topic is moderate; thus, there is a pressing need to improve the robustness of design to strengthen the evidence.

FullFigure 1 :
Figure 1: Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) fow diagram of the literature search and study selection process.

Table 1 :
Eligibility criteria according to the Population, Intervention/Exposure, Comparator, Outcome, and Study design (P(I/E)COS) criteria.