There are two main methods for choosing the right plants for your microforests.
Two methods for choosing plants
I call the two approaches the:
- Pure Miyawaki Method, and the
- Hybrid Miyawaki Method.
The Pure Miyawaki Method is based on replicating a locally occurring climax forest. Whereas the Hybrid Miyawaki method takes into account local climate change predictions.
The Hybrid Miyawaki method, like we employed in Canberra’s microforests, may lead to the selection of native Australian plants from non-local locations.
The Hybrid Method may be a more suitable approach for inland communities in southern Australia likely to be hotter and drier in the future.
Mikyawaki method of microforest making
The Miyawaki method of forest making was developed by Dr Akira Miyawaki in the 1970s in temperate Japan. Many parts of the country receive high rainfall compared to southern Australia.
Dr Miyawaki’s forest solution was a response to rapid urbanisation, industrialisation and natural disasters in Japan. His focus revolved around regenerating multi-layered plant communities of indigenous forests. He made over 1300 forests in Japan, Thailand, China and Africa.
Miyawaki created one of his earliest forests at Yokohama National University which receives on average 1700mm of rain per year. He claimed his evergreen broadleaf forests could withstand fire, earthquake, typhoons and tsunamis.
In the Pure Miyawaki Method, a local naturally occurring forest is surveyed to determine the mix of plants for the proposed constructed forest.
Miyawaki method includes strict rules
The Miyawaki method and its success has inspired forest makers across Australia. Yet it comes with a strict set of rules. These are:
- Survey a local climax forest community and replicate that
- Improve the soil organically (depending who you speak to you may need to improve the soil to depths of 1 metre)
- Mulch deeply (yes, use a thick layer of organic mulch).
As I discovered at the 2024 Miyawaki field trips in Tokyo and Yokohama, strict procedures exist around how plants are potted and mulch is tied down. Note: these rules don’t necessarily translate neatly to the Australian context.
Discover your future climate
Before you commit to a particular method of plant selection, it’s best to discover what your climate will be like in the future. In Australia, check out the Government’s Climate Analogue Tool.
This tool matches projected future rainfall and temperature for your location with the current climate experienced at another site. The tool gives predictions for 2030, 2050 and 2090 using a range of emissions scenarios.
Coast versus inland areas
Areas close to the coast may experience less devastating temperature increases than more inland areas. Buffering from flood or coastal incursion may be more important than harvesting local rainfall, particularly for high rainfall areas.
Canberra’s microforests
I was inspired by the Miyawaki method of dense forest making and wanted to replicate this method in Canberra.
However, 2019 was Australia’s hottest and driest year on record. Canberra received just 358 mm of precipitation. That’s just 8mm more than a semi-arid zone. And over the summer of 2019/2020 Canberra and NSW were devastasted by the Black Summer Fires that ripped through communities and Eucalyptus forest.
Australia’s forest communities are dominated by Eucalyptus, making up 78% of our forest types.
I used the Climate Analogue Tool to determine what Canberra’s future climate would be like. By 2090, Canberra’s climate would be akin to hot and dry inland town, like Forbes or Gilgandra. Using worst case scenarios the temperature could be up to 4.6C hotter with 25% less rainfall.
Eucalyptus forest too flammable
Coupled with recent bushfires, I predicted planting a flammable forest of local Eucalyptus predicted would be unpopular with the community.
Instead, I choose native trees with low flammability likely to do well in a hotter, drier future. Luckily, the Australian National University had a list I could use.
The number one tree for a hotter, drier future was the Kurrajong, Brachychiton populneus. This has become the signature tree of our microforests.
And we are trialling the Queensland Bottle Tree, Brachychiton rupestris too.
Our understorey include a mix of local natives and natives from hotter regions.
In our Canberra and Queanbeyan microforests we’ve used a mix of trees and shrubs like: Acacia, Callitris and Casuarina. Other understorey plants include Lomandra, Hardenbergia, Solanum and Viola. Not only are these plants suitable for microforests they are useful in home gardens.
To support our plants we incorporate water harvesting to capture rainwater that falls on the landscape.
Moruya Microforest
At the Moruya Microforest, located seven kilometres from the coast we employed the Pure Miyawaki Method of plant selection. Moruya’s future climate will be less impacted by climate change than Canberra’s.
At Moruya we replicated a local endangered ecological community, Dry Rainforest, with only 100 hectares left. This community is dominated by Ficus rubignosa, Port Jackson Fig and Backhousia myrtifolia, Grey Myrtle.
A water harvesting system helps support the newly planted rainforest through dry periods.
If you’d like to learn more about designing microforests join me at this introductory Microforest Maker workshop in 2025.
