Tiny Forests, Big Impact: How the Miyawaki Method Turns City Lots Into Dense Ecosystems in Just a Few Years
Across squares, schoolyards, and forgotten strips of land between apartment blocks, a new kind of green space is spreading across cities worldwide: small, densely planted patches that transform into forest-like ecosystems within just a handful of years. These tiny forests, sometimes called pocket forests or micro-forests, can occupy an area no bigger than a tennis court, yet they pack in hundreds of trees and shrubs from dozens of native species. The result is striking: the density of planting and the careful selection of species allow the young forest to reach structural maturity far faster than conventional afforestation, while quickly becoming home to dozens of species of insects, birds, and small mammals.
The method’s growing popularity responds to a very concrete problem facing modern cities, namely the shortage of green infrastructure in dense urban environments. Large parks and municipal forests require extensive land that simply doesn’t exist in city centers, whereas a tiny forest can be established almost anywhere a few dozen square meters of open ground can be found. That is why the approach has been embraced by local governments, schools, and non-profit organizations focused on tree planting and environmental education, all looking to show residents that bringing nature back into the city is possible even on a very small footprint.
The origins of the method: a Japanese botanist’s radical idea
Akira Miyawaki and the concept of climax vegetation
The method’s creator was Japanese botanist Akira Miyawaki, who spent decades studying natural forests across temperate and tropical zones, trying to answer a deceptively simple question: what vegetation would grow on a given plot of land if human activity had never disturbed it? This so-called potential natural vegetation became the starting point for his method. Rather than planting a random assortment of ornamental species, Miyawaki proposed recreating the full structure of a climax forest, made up of tree, shrub, and understory species typical of the local region. This approach was meant to ensure that the newly created forest would be resilient, self-sustaining, and capable of continued growth without ongoing human intervention.
From Japan to Europe and beyond
The first Miyawaki plantings appeared in Japan as early as the 1970s, mostly around shrines and industrial sites, where the fast-growing forest’s ability to rehabilitate degraded land was put to the test. Over the following decades the method gained traction in India, and from the middle of the last decade it began spreading rapidly across Europe, with early projects launched in the Netherlands, France, and the United Kingdom. Today tiny forests are growing in dozens of cities around the world, and interest in the approach is rising in Poland too, where pilot projects are now being carried out through partnerships between local governments, schools, and environmental foundations.
How a tiny forest is built, step by step
Soil analysis and site preparation
Before the first sapling ever touches the ground, the site earmarked for a tiny forest undergoes thorough analysis. Specialists examine soil structure and fertility, compaction levels, and the presence of contaminants, since urban land has often been heavily altered by previous construction or infrastructure. If the soil is poor or compacted, it is enriched with organic matter and mechanically loosened to a depth of up to a meter, allowing young roots to develop freely. This stage is often the most labor-intensive, but the quality of the substrate ultimately determines how fast the entire future forest will grow.
Choosing native species
The next step is selecting the tree and shrub species that would naturally occur on the site if left undisturbed by human activity. In temperate regions this typically means a mix of species such as oak, hornbeam, lime, maple, and rowan, complemented by a shrub layer of hazel, dogwood, or hawthorn. Structural diversity is essential, so the planting is designed in several layers, ranging from tall canopy trees through secondary species down to shrubs and ground cover. This multi-layered design is one of the main reasons a tiny forest starts functioning like a mature ecosystem so quickly.
Dense planting and the first years of care
A defining feature of the method is exceptionally dense planting, sometimes reaching up to three saplings per square meter, far more than conventional forestry practice. The plants then compete intensely for access to light, which forces faster vertical growth and quickly builds a closed, multi-layered canopy structure. For the first two to three years the site requires regular watering and the removal of invasive weeds, but after that period the root system is developed enough that the tiny forest becomes largely self-sufficient, requiring no further maintenance or irrigation.
Why tiny forests grow so fast: the science behind the phenomenon
Research on Miyawaki-style plantings suggests that such dense, species-rich forests can grow several times faster than trees planted in typical, sparser forestry arrangements. Several factors are at play here: intense competition for light accelerates shoot growth, species diversity reduces competition for the same soil resources, and a dense root network creates a natural system for exchanging water and nutrients between plants. In addition, the presence of many species at once encourages faster colonization of the site by soil microorganisms and mycorrhizal fungi, which support nutrient exchange between roots.
That said, it’s worth treating the most enthusiastic growth estimates with some caution, since actual growth rates depend heavily on local climate conditions, soil quality, and the specific species used. Regardless of the exact figures, observations from many cities show clearly that after just five or six years a tiny forest already resembles, in structure and canopy density, a much older natural forest, while conventional afforestation typically needs several decades to reach a comparable stage.
Benefits for cities: biodiversity, climate, and residents
Biodiversity and habitat for insects and birds
Even a small tiny forest can quickly become a refuge for dozens of species of animals and plants that were previously absent from the surrounding area. Dense undergrowth and a ground-cover layer offer shelter and food for pollinating insects, butterflies, and small mammals, while maturing trees attract birds looking for nesting sites. This kind of biodiversity matters not only ecologically but also educationally, since it lets city dwellers observe ecological processes up close that are usually associated only with distant forested areas.
Cooling the urban heat island and improving water retention
Concrete and asphalt surfaces in cities heat up far more than green spaces, contributing to the phenomenon known as the urban heat island. Even a modest cluster of trees can lower local air temperature by several degrees through shade and water transpiration from leaves, improving comfort for residents especially during summer heatwaves. In addition, a dense root network combined with soil enriched with organic matter absorbs rainwater far more effectively than sealed urban surfaces, reducing the risk of localized flooding after heavy downpours and supporting natural water retention in the ground.
Mental health and community education
Access to greenery close to home is linked to numerous mental health benefits, from lower stress levels to improved concentration and mood. Unlike distant forest complexes, tiny forests are literally within walking distance, meaning residents can visit them daily, while schools and kindergartens gain a natural outdoor classroom for hands-on lessons. Many projects also involve the local community from the planting stage onward, building a sense of shared ownership over the emerging forest and increasing the likelihood that it will be protected and valued for years to come.
Challenges and limitations of the method
Despite the enthusiasm surrounding tiny forests, the method has real limitations worth keeping in mind. Very dense planting means a higher per-square-meter cost for site preparation and saplings compared with conventional afforestation, which can be a barrier for smaller municipalities and organizations with limited budgets. In addition, the small footprint of any single tiny forest means it cannot replace extensive, fully functioning forest ecosystems or fulfill all the roles that large forest complexes provide, such as habitat for larger mammals that require extensive territory.
Critics also point out that some of the published research on tiny forest growth rates comes from projects run by the very organizations promoting the technique, highlighting the need for further independent scientific study. None of this diminishes the real value of tiny forests as a complement to, rather than a replacement for, a broader strategy of protecting and restoring urban green space. The best results come from combining tiny forests with other measures, such as protecting existing old-growth trees, creating ecological corridors, and establishing wildflower meadows.
Tiny forests in practice: early projects and enormous potential
Cities around the world, much like many European metropolises, are grappling with a shortage of green space and the effects of the urban heat island, which is why interest in the Miyawaki method keeps growing. Early pilot plantings have appeared next to schools, on former industrial sites, and as part of programs to revitalize neglected urban plots, with local authorities looking for ways to deliver fast, visible greening results. Companies are increasingly getting involved in these initiatives too, through corporate social responsibility programs that treat tiny forests as a concrete, measurable contribution to climate and local nature protection.
The potential of this method is enormous given the number of underused, neglected patches of land in cities: abandoned lots, roadside strips, squares, and school grounds could all be transformed within a few years into small but genuinely thriving forest ecosystems. The One More Tree Foundation has spent years running projects focused on tree planting and restoring greenery in cities, and anyone curious about how practical support for such initiatives looks can visit the foundation’s website to learn about current projects and ways to get involved.
How you can get involved
Supporting the tiny forest movement doesn’t require owning land or having specialist botanical knowledge, since it’s usually local organizations and foundations that coordinate the whole process, from soil analysis to species selection. Individuals can contribute in a number of ways, including:
- joining planting events organized by foundations and local governments,
- financially supporting specific urban greening projects,
- flagging potential sites to local authorities that could host a new tiny forest,
- educating neighbors and family about the benefits of urban greenery.
Companies, meanwhile, are increasingly organizing employee volunteering days combined with tree planting, treating it as a way to build team spirit while making a real contribution to environmental protection. If your organization is looking for an experienced partner for this kind of initiative, it’s worth checking out the corporate offer, which shows how business goals can be paired with a concrete, measurable impact on climate and biodiversity.
Conclusion: a small forest, a large impact
Miyawaki tiny forests show that bringing nature back into cities doesn’t have to mean massive, costly investment or decades of waiting for results. Even a small patch of land, properly prepared and densely planted with native species, can turn into a dense, multi-layered ecosystem within just a few years, one that supports biodiversity, helps mitigate the effects of climate change, and improves quality of life for residents. It’s a solution that blends science, community involvement, and concrete, measurable environmental benefits.
Every new tiny forest planted in a city is a step toward a greener, more climate-resilient future, and tangible proof that individual actions matter. If you’d like to learn how to get involved in tree planting and support initiatives like this in your own community, visit the One More Tree Foundation homepage, where you’ll find current projects and concrete ways to help build a greener future for cities everywhere.
