Akira Miyawaki spent much of his career mapping potential natural vegetation — the plant communities that would establish themselves on a given site if human activity stopped entirely. His planting method draws on this work: rather than importing ornamental trees, you identify the native climax species for the location and plant them together at high density, compressed into a timeline that mimics natural forest dynamics without the century-scale waiting period.
A Miyawaki-method forest at Edappally, Kerala — showing the dense, multi-layered canopy typical of the approach. Source: Wikimedia Commons (CC BY-SA 4.0)
Adapting the concept for Poland
Poland sits within the temperate broadleaf and mixed forest zone. The potential natural vegetation across most of the country's lowlands includes pedunculate oak (Quercus robur), hornbeam (Carpinus betulus), small-leaved lime (Tilia cordata), Norway maple (Acer platanoides), and field maple (Acer campestre), with hazel (Corylus avellana) and elder (Sambucus nigra) in the shrub layer. These are the foundation of any Miyawaki planting in a central or northern Polish city.
What changes when moving from rural forest restoration to urban micro-forests is the site condition. Urban soils are typically compacted, nutrient-poor in organic matter but sometimes high in construction rubble, and subject to heat-island effects. Several practitioners working in Warsaw, Kraków, and Wrocław have reported that soil preparation — breaking compaction, adding biomass — is proportionally more important than the plant selection itself in degraded urban plots.
Plot size and planting geometry
The classical Miyawaki protocol calls for mixing three to five species per square metre across canopy, sub-canopy, shrub, and groundcover layers, planted in a randomised grid. For urban Poland this creates a practical challenge: most available plots in park margins, schoolyards, or industrial verges are between 50 and 300 square metres. On the smaller end, species diversity must be reduced to avoid the edge-effect problems that arise when a tiny plot is overwhelmed by a single aggressive species.
Planting structure overview
- Canopy layer (15–25 m at maturity): pedunculate oak, small-leaved lime, hornbeam
- Sub-canopy layer (6–15 m): field maple, wild cherry, bird cherry
- Shrub layer (1–6 m): hazel, hawthorn, spindle, elder
- Groundcover layer (0–1 m): dog rose, bramble, ivy, wood anemone
The planting geometry is usually a 50 × 50 cm or 60 × 60 cm grid, with species randomly distributed so that no single type clusters. The apparent disorder at planting resolves within two growing seasons as taller and more vigorous species begin to overtop neighbours, initiating the natural thinning process.
Documented projects in Polish cities
Several city councils and NGOs have carried out Miyawaki-method plantings in recent years. Warsaw's Lasy Miejskie programme has included experimental dense-planting plots in the buffer zones of managed urban forests. In Kraków, civic groups associated with local environmental education initiatives planted a small demonstration plot at a primary school in the Podgórze district. Exact outcome data from these projects is not consistently published, but practitioners have shared observations through the IUCN Urban Forests networks and at domestic forestry conferences.
Soil preparation as the limiting step
Before any planting, the standard preparation sequence involves removing existing vegetation (including roots of invasive species like Robinia pseudoacacia if present), breaking soil compaction to at least 50 cm depth, and adding a substantial layer of mixed organic material — typically composted bark, wood chip, and green compost at a combined depth of 15–20 cm. Some projects have also incorporated mycorrhizal inoculants at planting time, though evidence for their benefit in already-inoculated urban soils is mixed.
The soil amendment serves two purposes: it improves water retention and root penetration in compacted urban ground, and it provides the nutrient pulse that drives the initial explosive growth Miyawaki-method plantings are known for. Without this step, survival rates in the first summer can be significantly lower, particularly during the dry spells that occur in Poland from June through August.
External references
Background on potential natural vegetation mapping: ScienceDirect — Miyawaki Method. Urban forest policy context: European Environment Agency — Urban Tree Cover.