Norwalk's Miyawaki
Micro-Forest
Who was Dr. Akira Miyawaki?
The Miyawaki method is one of the most effective methods for establishing rapid tree canopy growth in degraded soils. This method establishes a pioneer forest within 20-30 years, allowing a native forest to outcompete invasive and weedy plants in the long run.
Dr Akira Miyawaki (1928–2021) dedicated his life to research and literature surrounding the creation and healing power of native forests, adapting this method based on decades of experience advocating for them. After studying biology at Hiroshima University and researching plant ecology in Japan and Germany, Miyawaki developed the concept of potential natural vegetation (PNV), planting the species that the land is naturally suited to support, taking inspiration and plant communities from remnants of indigenous forests found at temples, shrines, and cemeteries.
By the 1970s, Dr. Miyawaki began to apply his research to the developed method of planting dense, multilayered forests. On the ground, he instructed plantings in 1700 sites over his career, 1400 of which were within Japan. With large plantings, professor Miyawaki would always take an hour or so to instruct group leaders, instilling a sense of responsibility and making sure everyone understands the assignment. His work is the scientific foundation behind the densely planted, native-species micro-forests that have spread around the world, for which careful species selection, soil preparation, and long-term stewardship are key.
What makes a Miyawaki Microforest?
A Miyawaki microforest is defined by more than simply planting trees densely:
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It begins with selecting the correct native species based on the site’s potential natural vegetation (PNV), followed by soil remediation and preparation.
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According to Mio Urata, Dr. Miyawaki's pupil of 20 years, the soil should be tilled and amended (often with ~4 kg of soil amendment per square meter) with any slopes reinforced using rocks or sticks; some projects have also used fence terraces on slopes.
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The planting stock is ideally 2-3 year-old potted seedlings, with fully developed root systems; smaller pots can make seedlings easier for volunteers to handle while keeping roots vigorous.
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Planting emphasizes the principle of “don’t plant big trees, plant trees that have the power to grow into big trees,” while meadows can be incorporated, particularly along edges to support pollinators.
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Establishment is followed by active stewardship, including maintaining 4–6 inches of mulch in pathways, monitoring, community engagement, and adapting the forest as plants grow and become shaded.
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Some plantings incorporate wildflower meadows, like our own micro-forest in Norwalk which aims to engage community with benches and mulched pathways.
A Miyawaki micro-forest is ultimately a deliberately designed, densely planted native forest ecosystem whose structure, soils, species composition, and long-term stewardship are intended to accelerate ecological development on a relatively small site.
Our Norwalk Forest
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In 2024, NRWA received a pavement to micro-forest grant totaling $150,000 from the CT Dept. of Energy and Environmental Protection. This 5,500 square foot urban forest containing over 1000 native trees and shrubs in addition to countless grasses and wildflowers, located at Meadow Street park in South Norwalk, will help cool and clean the air, filter storm water, and provide habitat for wildlife in an area that previously had just 16 municipal trees.
Invasive Norway maple saplings weeded from our Norwalk microforest.
As of the forests second year, less than 10 total woody perennial plants (trees and shrubs) of over 1000 in the forest's entire lifecycle have died, and we continue to water the forest and monitor it for disease as needed. After assessing the state of invasives and weeds throughout the forest, results were promising. Across the different sections of the forest, weed density ranges from close to 1 weed per square foot to, more commonly, just 0.1 weeds per square foot (with an average weed density under 0.2 per square foot). Our forest is very healthy and amazingly vibrant, and we can't wait to see what it becomes in the next few years!
The Norwalk microforest in year 2 of growth, summer 2026