Urban community gardens as green infrastructure in densifying cities: contributions, constraints, and possibilities

Cities around the world face an intensifying debate over whether urban densification necessarily comes at the expense of greenness, biodiversity, and everyday interactions with nature (Haase et al., 2017;McDonald et al., 2023;Wicki et al., 2021). Currently over 80% of the US population lives in urban landscapes; and by 2050, more than twothirds of the world will live in urban areas (United Nations, 2018). Cities are often nature-poor because the built environment is optimized for human constructs rather than for nature (Ossola & Niemelä, 2018), leading to an extinction of experience where urban dwellers have lost opportunities to interact with nature (Soga & Gaston, 2016). This has in turn led to changes in attitudes and understandings of how to interact with nature (Lin & Andersson, 2023).Besides the loss of green space, increasingly compact cities face food security issues (McClintock et al., 2018;Ruel et al., 2017). Food security is defined by "when all people, at all times, have physical and economic access to sufficient, safe and nutritious food that meets their dietary needs and food preferences for an active and healthy life" (World Food Summit, 2006). The loss of private land for gardening and the proliferation of busy, urban lives has led to greater dependence on commercial food, which have become increasingly expensive post-COVID19 (O'Hara & Toussaint, 2021). Further, the existence and potential expansion of "food deserts", areas where grocery stores are non-existent, exacerbates food insecurity and poor nutrition for urban residents (Miller, 2020).In contrast to these challenges, urban gardens provide a unique set of food and wellbeing solutions within dense city environments. Urban agriculture (including urban community gardens) has expanded in the US over the past 30 years, in part due to land tenure policy changes that provide use of vacant land for gardening (Pawlowski, 2018) and out of concern for food justice and food sovereignty for under-served communities (Sager & Petrosino, 2025).Drawing on a long-term, multidisciplinary research program conducted since 2013 on urban community gardens in the California Central Coast, we use this system as a lens to explore how community gardens may function as one form of green infrastructure within increasingly compact urban development. While grounded in a specific regional context, the mechanisms discussed-such as vegetation heterogeneity, social governance, and multifunctionality-are relevant to dense cities globally and are intended to stimulate broader dialogue rather than prescribe a universal model. Our decade-plus history of work has facilitated a deep understanding of how local and landscape management influences a broad range of biodiversity and ecosystem services within the urban environment as well as specific contributions to food production and gardener well-being. Although gardens vary substantially in local habitat management, landscape composition, and gardener demographics, certain OFFICIAL management strategies and support mechanisms are essential to maximise gardener benefits.The objective of this opinion article is to draw on the accumulated research insight to unpack tensions, trade-offs, and possibilities surrounding urban community gardens in dense cities. In doing so, we aim to contribute to ongoing debates about how greenness, density, food systems, and social well-being might coexist under conditions of increasing urban land pressure. Below we provide evidence of how community gardens can make much needed contributions to local biodiversity and ecosystem services within the spatial constraints of urban landscapes.Urban community gardens are highly heterogeneous in size, form, and function, encompassing community gardens, home gardens, rooftop gardens, easements, and other small-scale cultivated spaces embedded within dense urban matrices (Lin et al., 2015). This heterogeneity distinguishes community gardens from more uniform urban green spaces such as lawns or formal parks and is central to their biodiversity potential despite their limited spatial extent (Threlfall et al., 2017). This range of garden types allows for a diverse set of vegetation structures to contribute to the edible urban landscape across both public and private lands (McLain et al., 2012).Because plot management is typically decentralized and guided by individual or household preferences, community gardens often exhibit high vegetation diversity, including mixtures of crop species and varieties, ornamental plants, shrubs, and trees.In compact urban environments where large contiguous green spaces are rare, this fine-grained vegetation diversity can create ecological niches that support a wide range of taxa at very small spatial scales (Hall et al., 2017). Gardener motivations, demographics (e.g., gender, class, ethnicity), and experience (e.g., hours spent gardening, agricultural employment), can shape plant diversity and composition (Burdine & Taylor, 2018;Clarke et al., 2014). Our research has shown that urban gardens can support high plant diversity, often >120 crops and >70 ornamental plant species in a single ecoregion.Our long-term research demonstrates that some urban community gardens can support exceptionally high plant richness within a single city or ecoregion. Importantly, this richness is not uniform across gardens but varies with gardener demographics, cultural identity, motivations, and time investment (Philpott et al., 2020). Local vegetation management in community gardens strongly influences animal communities, particularly pollinators and natural enemies of pests, which contribute to ecosystem functions that support crop production (Dainese et al., 2019;Jha et al., OFFICIAL 2023;Vasiliev & Greenwood, 2021). Empirical studies consistently show that floral richness, flowering area, and plant structural diversity are key drivers of pollinator and predator abundance and richness in urban garden systems (Hall et al., 2017;Otoshi et al., 2015;Plascencia & Philpott, 2017;Quistberg et al., 2016).Differences in garden size, management intensity, surrounding land use, and disturbance regimes can lead to highly variable ecological outcomes, even within the same city. In community gardens, these services are mediated by both local vegetation management and landscape context, underscoring that biodiversity outcomes cannot be inferred from garden presence alone. These patterns highlight the need for future research to move beyond species counts and examine how biodiversity in community gardens translates into functional outcomes, such as pollination effectiveness or pest suppression, under the constraints of dense urban environments.We posit that future research should expand upon our understanding of the management practices that promote biodiversity and well-being benefits in urban gardens such as adaptive vegetation management. This includes iterative, site-responsive practices that adjust plant selection, structure, and maintenance in response to constraints common in dense cities, including building shade, soil contamination, limited space, and water scarcity (Pickett et al., 2022). Examples include the use of shade-tolerant crops, raised beds with imported soils, mulch-based water retention, and flexible cropping strategies suited to temporary or compact sites. A renewed focus toward adaptive vegetation management in urban agriculture will have significant benefits for biodiversity-mediated ecosystem services.Urban community gardens can contribute meaningfully to food access, dietary diversity, and food agency within dense urban environments, but they should not be interpreted as a comprehensive solution to urban food insecurity. Within gardens, crop and plant species selection is highly dependent on food preferences (Burdine & Taylor, 2018), access to resources such as compost or seeds (Erskine et al., 2024), and garden rules that restrict chemical/water use and gardening infrastructures (e.g. for climbing plants) (Egerer & Fairbairn, 2018).Our gardener surveys revealed that higher social diversity (e.g., age, education, income, languages) within a garden can lead to a higher diversity of plants and food products cultivated. Although gardeners have a variety of motivations for participating in a community garden, many gardeners (over 48%) noted food production as the primary reason for gardening, including the idea of feeding their family, sharing food, accessing cultural foods or medicinal plants (Lin et al., 2024). Half of gardeners estimated a OFFICIAL harvest of 1-10 pounds of food/week, consistent with our field measurements of tomato, squash, and peppers, which showed yields of about 4 pounds/week. Based on the 2024 prices of vegetables found in nearby shops, this was approximately a savings of ~$16 per week for these gardeners (Lin et al., 2024).While this amount of savings is helpful for many gardeners, it is important to point out that gardeners exhibited substantial variation in their production, where some state that they are near self-sufficient on what they produce, while others noted that they were still food insecure at times (Lin et al., 2024). Gardeners who spent more time in the garden reported higher food security, but gardeners with larger families or on lower incomes were more food insecure. Thus, gardening benefits were not distributed evenly or towards the most food-insecure families.Our findings highlight that food-related benefits from community gardening are substantial but uneven. Differences in time availability, household size, income, and land tenure mediate the extent to which gardens enhance food security outcomes (Du Toit et al., 2022;Huq & Deacon, 2025). As such, community gardens function best as complementary infrastructures within broader urban food systems rather than as stand-alone interventions.Urban gardens have the potential to bring urban dwellers into closer contact with natural elements to interact with nature and to grow "biophilia" (sensu Wilson 1984, human's innate tendency to seek connections with nature) (Hartig et al., 2014;Lin et al., 2018;Wilson, 1986). Gardens can improve access to urban greenspace especially if they are designed and enhanced to represent highly diverse and complex spaces that mimic natural systems and potential build human connection with nature (Nicholls et al., 2020).The tremendous variety of urban garden vegetation structure and diversity in a compact and accessible space allows for unique opportunities to enhance an individual's interaction with nature (Hanson et al., 2021). Gardeners and visitors can reconnect and experience different types of nature elements, from forest-like urban orchards to small garden beds of food products, to herb or medicinal bushes along the walkways, allowing for different types of entry points of interaction (Lin et al., 2018). Urban gardeners come into direct contact with nature through the corporeal interaction of handling soil and touching plants.Such experience can help individuals develop continued curiosity and fascination for the natural world (Ganzevoort & van den Born, 2019). Place-based education and OFFICIAL outdoor education have shown how nature contact can lead to a better understanding of the environmental world and processes, such as pollination or changes in weather patterns, and how they affect plant growth (Faber Taylor et al., 2022). Gardener education, such as attaining extra courses through a Master Gardener class as well as experiences in gardens, can affect individual management choices (Gonzales, 2024;Lin et al., 2025). Gardener knowledge can lead to better plant selection based on microclimate conditions (Lucatero & Fairbairn, 2025) as well as identifying beneficial animals (pollinators, natural enemies, and herbivores) that support food production (Gonzales, 2024).Urban community gardens are increasingly recognised as forms of social infrastructure within dense cities, providing spaces where social interaction, collective action, and community cohesion can emerge in otherwise fragmented urban landscapes (Klinenberg, 2018). Rather than functioning solely as sites of food production, community gardens create repeated, place-based opportunities for interaction that support relationship building, shared learning, and collective stewardship.Survey data from our study sites indicate that while food production is a primary motivator for many gardeners, participation is also strongly driven by opportunities for relaxation, social connection, physical activity, and psychological restoration, reflecting the multifunctional nature of these spaces (Lin et al., 2025). Community gardening spaces support mental health (Lampert et al., 2021), where positive past and present nature experiences can promote emotional and psychological well-being (Koay and Dillon 2020). Moreover, community garden participation may have a positive impact on physical health, such as reducing body weight and hypertension, and increasing physical activity and food knowledge to promote better nutrition (Kunpeuk et al., 2020).In compact urban landscapes, community gardens offer rare spaces where social ties can be formed across age, cultural background, and socioeconomic status, supporting community cohesion and informal social networks (Egerer et al., 2018). Gardens provide a space for people to meet and exchange ideas, encourage cross-cultural connections, and promote environmental stewardship (Kingsley & Townsend, 2006;Ossola & Niemelä, 2018). Indeed, past work has shown that mental health benefits come largely from social-connection and processes like collaborative place-making labour that engender connectedness, collaborative learning, empowerment, and a connection to nature (Zinaic et al., 2025). Our results provide support for these wideranging well-being benefits in urban garden spaces. These benefits are not automatic, but are mediated by garden governance, norms of inclusion, and opportunities for shared decision-making, highlighting the importance of social processes alongside physical design (Anguelovski et al., 2022). OFFICIAL Urban community gardens illustrate both the possibilities and the tensions inherent in efforts to create cities that are simultaneously dense and green. While they do not resolve structural challenges related to land access, inequality, or food insecurity, they reveal how multifunctional green spaces can coexist with densification when supported by appropriate governance, design, and social investment. At the same time, the social benefits of community gardens are not evenly distributed. Previous work has shown that exclusionary rules, insecure land tenure, or unequal access to time and resources can limit who is able to participate fully, particularly in more marginalised communities.These findings suggest that urban community gardens can function as important social infrastructures in dense cities, while also revealing the governance and equity challenges that shape how social benefits are realised in practice.The perspectives advanced in this article draw on a decade-long program of interdisciplinary research comprising multi-year field studies, biodiversity sampling, and gardener surveys across urban community gardens. These studies examined vegetation composition, beneficial insect communities, food production, and gardener experiences. Rather than synthesising evidence through a formal systematic review, this article reflects on accumulated findings from this research trajectory to inform broader conceptual discussion appropriate to the ongoing dialogue that asks whether cities can be both dense and green.In highly dense cities, land availability represents a central constraint rather than a neutral background condition (Anguelovski et al., 2018;Meerow & Newell, 2019). Community gardens rarely persist in the absence of negotiation, governance, and political prioritisation, particularly where urban land values are high. While early expansion of community gardens in some cities has relied on vacant or under-utilised land, such spaces are increasingly scarce in compact urban environments. As a result, contemporary community gardens are emerging across a wider array of urban forms, including rooftops, podium levels, school grounds, easements, temporary sites, and hybrid public-private spaces.The social, ecological, and food-related benefits of urban community gardens extend well beyond food production alone. However, realising these benefits at scaleparticularly in dense cities-requires deliberate policy choices that address land access, governance, and long-term institutional support under conditions of increasing urban land pressure. As reviewed above, community gardens can engage diverse populations, including immigrants, Indigenous peoples, women, seniors, youth, and people experiencing disability or mental health challenges. In many cities, they also represent important spaces for accessing culturally appropriate foods, medicinal OFFICIAL plants, and social support networks. At the same time, access to these benefits is uneven, and in dense cities is often shaped by zoning restrictions, tenure insecurity, and unequal access to resources such as water, tools, and time (Zinaic et al., 2025).A persistent barrier across cities is insecure land tenure. Community gardens are frequently located on land earmarked for future development, rendering them vulnerable to displacement precisely as urban density increases, reducing access to food, cultural plants, and medicinal resources in poorer areas of the urban landscape (Clarke et al., 2014;Glowa et al., 2019;Singh et al., 2025). In high-density contexts, this insecurity is not incidental but reflects deeper tensions between short-term land value capture and long-term public benefits associated with green infrastructure (Anguelovski et al., 2018;Salters et al., 2024). Moreover, resource access, rules, and social norms may impact gardener agency to grow food at sufficient quantities for their family and friends (Egerer et al. 2020). For community gardens to remain in the urban landscape, one cannot assume that low-value or vacant land will always be available; Having long-term support for urban community gardens requires governance frameworks that recognise gardens as multifunctional green infrastructure delivering co-benefits across public health, biodiversity conservation, climate adaptation, and social cohesion (Delshad, 2022).Municipal governments can support urban community gardens through a combination of concrete policy mechanisms, including long-term or rolling land leases, zoning provisions that recognise gardens as legitimate land uses, affordable or tiered water pricing, administrative support, and plot-fee structures designed to remain accessible to lower-income households (Carvalho et al., 2022;Fox-Kämper et al., 2018). In some contexts, integrating community gardens into broader urban planning frameworkssuch as climate adaptation strategies, public health initiatives, or open-space plansmay provide more durable support than stand-alone urban agriculture programs (van der Jagt et al., 2017). Governance arrangements also matter. Inclusive, participatory governance models can enhance social cohesion and stewardship, whereas overly restrictive rules or gatekeeping practices may unintentionally exclude those most likely to benefit (Abrantes et al., 2025). Nevertheless, community gardens should not be treated as a low-cost substitute for addressing structural food insecurity, housing inequality, or green space deficits. Their value lies in complementing-rather than replacing-broader social and urban policy interventions.Overall, policy choices surrounding land access, governance, and integration into urban planning will play a decisive role in shaping whether community gardens remain marginal and temporary, or become enduring components of dense and green urban futures.