Research & reports

· Wikipedia（日本語版） · Japan

The Japanese Wikipedia article on rooftop greening traces its origins to the Hanging Gardens of Babylon around 600 BCE, and in Japan cites the 1934-built Asakura Museum of Sculpture as a surviving early example, with Nihonbashi Takashimaya among the pioneers from the late 1960s onward. It lists effects including heat island mitigation, improved insulation, sound reduction, increased water retention, air purification, and improved landscape, dividing methods into lightweight thin-layer greening using sedum or lawn versus full garden-style greening with flower beds and shrubs.

株式会社アグリメディア · 株式会社アグリメディア · Japan

The official site of 'Sharebatake', a members-only rental farm plot service operated by AGRIMEDIA Co., Ltd. Seeds, seedlings, fertilizer, and tools are provided on-site with experienced advisors on hand, letting members show up 'empty-handed'. It operates nationwide across regions including Tokyo, Kanagawa, Chiba, Saitama, Aichi, Osaka, Hyogo, Kyoto, and Fukuoka, with about 118 farm sites and roughly 15,138 plots as of end of July 2026.

ローカルフードサイクリング株式会社 · ローカルフードサイクリング株式会社 · Japan

The official site of LFC Compost, a bag-based home composting product for kitchen scraps operated by Local Food Cycling Inc., part of the Borderless Group. Users simply 'add' food waste and 'lightly mix' it to compost, with support via LINE chat, balcony-gardening classes, and compost consultation/collection events also offered. Its subscription compost-set product has received 1,016 reviews with a 4.51/5 rating.

Ana Catarina Morais, Akira Ishida · Frontiers in Sustainable Food Systems · Japan

This research investigated factors encouraging Japanese households to engage in composting, applying the theory of consumption values (TCV) and evaluating hypotheses using ordinal partial least squares structural equation modeling. Findings indicate that household composting in Japan is influenced by social approval, behavior visibility, composting knowledge, convenience, interest in gardening/farming, and individual availability. Factors like emotions, gender, housing type, and household size did not significantly impact composting practice.

新保 奈穂美 · 世田谷区 都市農業関連研究報告 · Japan

Analyses Tamaribatake, a community garden piloted under Setagaya's proposal-based partnership programme, clarifying conditions that secure participants' freedom without rigid rules and offering operational insight for municipally supported community farms.

Ken Muramatsu, Akane Bessho, Takahiro Yamazaki, Akiko Iida, Makoto Yokohari · Journal of the City Planning Institute of Japan · Japan

This study examined "Katte-Kosaku," unauthorized cultivation on the riverbed of the Hanami River in Chiba City, Japan, from a social well-being perspective. It found that the practice has a welfare function that improves the quality of life of socially vulnerable people, and that a certain number of people in the surrounding community tolerate the activity.

特定非営利活動法人 Co.to.hana, 金田 康孝 · 国土交通省 都市と農・緑が共生するまちづくりに関する調査（平成29年度） · Japan (Osaka)

Co.to.hana's second-year MLIT study codifying how to reproduce Minna-no-uen's effects — activity data analysis since 2011, international comparables, intermediary-organisation needs, trial social-impact metrics, published as this report and at minnanouen.jp/research.

グエン トラン イェン カン, 涼 村田 · Institutional Repositories DataBase (IRDB) · Japan (Tokyo)

This study clarifies users' roles in urban space creation by examining two renovated open spaces with urban gardening (OSUG) in Tokyo. Through a mixed survey, the spatial settings and user experiences were analyzed, revealing quality parameters such as "usage," "space affordance," and "image of identity." These factors illustrate seven OSUG scenarios, from private resting spots to public playgrounds and community gardens.

特定非営利活動法人 Co.to.hana, 金田 康孝, 西川 亮 · 国土交通省 都市と農・緑が共生するまちづくりに関する調査（平成28年度） · Japan (Osaka)

First-year MLIT-commissioned study by Co.to.hana validating usefulness and replicability of community farms on urban unused land, using Kitakagaya Minna-no-uen as the model — surveys, environmental monitoring, stakeholder interviews and an expert panel producing a start guide and dissemination roadmap.

Yugo YAMAMOTO, Asami ORITA, Motoyuki NAGAI · Studies in Regional Science · Japan (Osaka)

A questionnaire survey was conducted among LOHAS (Lifestyles of Health and Sustainability) and general consumers in Osaka Prefecture to identify sustainable lifestyles related to food production and consumption and evaluate their effect on CO2 emissions. LOHAS consumers tended to participate in local food production activities and make purchasing decisions based on health and environmental consciousness. Their total daily life CO2 emissions were 15% lower than regular consumers, but their transportation-related CO2 emissions were higher due to roundtrips to local farm shops.

Takao Koyama, Takayuki Minagawa, Tsutomu Hanai, Hideki IDOTA · Journal of Structural and Construction Engineering (Transactions of AIJ) · Japan (Tokyo)

The validity of using residential design live loads for rooftop gardens has not been confirmed. This study proposes new design live load values for rooftop gardens based on building survey results from 24 steel-framed houses in the Tokyo area. The proposed design live load value will enable rational structural design for residences with rooftop gardens.

埼玉県 · 埼玉県 · Japan

This Saitama Prefecture guide on rooftop and wall greening methods cites the Building Standards Act Enforcement Order's live-load table and explains that an existing ordinary house roof can carry roughly only 60 kg/sqm once seismic force is factored in. Covering a roof with 10 cm of natural soil (specific gravity 1.6-1.8) would add 160-180 kg/sqm, exceeding that limit, so it recommends lightweight artificial soils (specific gravity 0.6-1.0) and notes the need for root-barrier sheets to protect waterproofing layers and for automated irrigation.

Ryozo Noguchi, Shuya Abe, Takahiro Saito · Agricultural Information Research · Japan

This study in Japan constructed a design model for Japanese hoes used in community and home gardens, aiming to tailor them to users' physiques, strength, and ease of use, employing Kansei Engineering. Based on three-point task analysis and extracted Kansei elements of usability, a network-structured design model was proposed. The relationships between handle length and ease of work, and moment of inertia and ease of swinging, were experimentally determined using the Magnitude Estimation method, revealing the potential to evaluate commercial hoes and improve designs according to user height and muscle strength.

智 藤田, Satoshi FUJITA · Institutional Repositories DataBase (IRDB) · Japan

At Keisen Women's College farm in Japan, the potential of using Low-Input Sustainable Horticulture (LISH) and vegetable gardening as environmental education materials was investigated over 15 years, starting in 1984. The study found that 16 different vegetable varieties could be grown organically, but cucumbers, other fruit/vegetables, and Cruciferae were virtually impossible to grow organically. However, damage could be reduced for some varieties through specific cultivation methods, and the vegetable garden was found to maintain beauty even in cold seasons and provide a suitable hands-on learning experience for environment and food.

Isami Kinoshita, Jin Yoshikawa · Journal of the City Planning Institute of Japan · Japan

This study identified the meaning and role of edible landscapes in urban residential areas by comparing three districts in Japan: Nezu, Taishido, and Kokubunji-shinmachi. Through observation, interviews, and questionnaires, five common meanings and roles were found, including providing fresh food, fostering memories, promoting communication, preserving folk customs, and encouraging ecological thinking despite maintenance challenges.

Hyeong-Seok Choi, Yoshiyuki Amemiya · Journal of The Japanese Institute of Landscape Architecture · Japan

Artificial planting soil layers used in settings such as rooftop gardens typically have a two-layer structure: a coarse drainage layer and a planting layer. Assuming no irrigation, this study examined the required layer thickness based on soil physical properties and weather conditions. Using 30 years of rainfall records for Tokyo, the logarithmic cumulative distribution of the number of days between rainfalls was well fitted by a normal distribution, with the number of days between rainfalls corresponding to 95% and 99% occurrence probabilities being 29 and 64 days, respectively. Numerical calculations for a two-layer system with a 100 mm lower layer examined the relationship between layer thickness and the time until the planting layer wilts on average from initial moisture; at 99% probability, the required planting layer thickness was 236 mm, roughly half the 424 mm required for a single-layer system.