Background

Set within a circle, a meandering pathway with various types of shubbery and trees on either side. With images of butterflies, a lizard and a bird in the foreground. A hazy silhouette of iconic Los Angeles skyscrapers in the back. Four distant birds in flight on the left. A bird alighting on a bush. Logo reads LA Micro Forests.
Micro forests (also called pocket forests, mini forests, and tiny forests) are densely-planted, multilayered indigenous forests planted in urban spaces which act as self-sustaining ecosystems that reconnect fragmented habitat and restore biodiversity.

The Miyawaki Method

The micro forest method is inspired by the work of Japanese botanist and ecologist Akira Miyawaki (1928 – 2021), who pioneered a style of forest creation in Japan known as the Miyawaki Method.

Portrait of Akira Miyawaki in sunhat with trees in background.
Akira Miyawaki, pioneer of the Miyawaki Method of Afforestation.
Front approach to Rinnoji Temple in Japan in 2008 with long, concrete walkway and hundreds of small tree saplings planted en masse on either side of the walkway. Buildings and other structures are visible on the periphery.
Example of a Miyawaki forest (Japan, 2008)
Front approach to Rinnoji Temple in Japan in 2014 with long, shady, concrete walkway and dense, tall trees on either side of the walkway. No buildings are visible, only the forest greenery and the walkway itself.
Example of a Miyawaki forest (Japan, 2014)

The Miyawaki forest

There are four layers of a conventional Miyawaki forest: canopy tree, tree, sub-tree, and shrub.

Diagram of Miyawaki forest layers with labels indicating canopy trees, trees, sub-trees, and shrubs.

The Miyawaki method involves the randomized planting of small saplings of various indigenous shrubs and trees (grown from local, regionally adapted seeds) in very close proximity together, where no two trees or shrubs of the same height are planted side by side.

This complex layering ensures that the trees are able to grow to their ideal sizes without initially competing with a neighboring tree of the same height, while at the same time, maximizing every bit of space in the forest. Over time, as the trees mature, natural thinning does occur, with stronger trees outcompeting the weaker ones.

Miyawaki forests around the world

Because of their potential to create major impacts in minor spaces, even spaces as small as 12’ x 12’, people around the globe are using this method to restore nature in both urban and rural areas.

Temperate and tropical climates with higher rainfall naturally lend themselves to this method, but it is now being tested in drier and harsher Mediterranean climates as well.

See domestic and international examples of Miyawaki forests at SUGi Project.

Painting of Planet Earth with North America and part of South America.
BUT...how do we adapt the Miyawaki Method for our harsher, drier climate in LA?
Side-by-side image of natural temperate forest in Japan with a natural chaparral hillside in Los Angeles. Pensive emoji face in the center of the two images with a thought bubble that depicts a tree emoji. JapanLos Angeles

The LA micro forest

Diagram featuring the layers of an LA Micro Forest indicating canopy trees, trees, sub-trees, and shrubs & perennials.
Setting up the forest for maximum success in the LA region requires some changes and adaptations to the traditional Miyawaki Method to account for differences in climate and natural survival strategies of the region’s native flora. As such, micro forests in LA have been modeled off of natural woodland habitats, particularly southern oak woodlands and closely associated plant communities.
Smaller version of Miyawaki forest layers. Part of side-by-side comparison of diagrams featuring Miyawaki forest layers and Los Angeles micro forest layers.
Miyawaki forest
Smaller version of Los Angeles micro forest layers. Side-by-side comparison of diagrams featuring Miyawaki forest layers and Los Angeles micro forest layers. Los Angeles micro forest

Changes for LA micro forests

Specific changes which were made to the Miyawaki Method to make it more applicable to LA’s natural ecology are summarized below:

  • The inclusion of herbaceous perennials within the lowest layer of the forest
  • A higher ratio of shrubs and herbaceous perennials and lower ratio of trees compared to a traditional Miyawaki forest
  • A reduction in plant density (from 3 trees/shrubs per 10 sq.ft. to 1 trees/shrubs per 9 sq.ft.)
  • A reduction/elimination of tilling as a soil prep strategy
  • An elimination of manure as a fertility strategy. Compost (for the addition of beneficial soil microbes more so than fertility) used instead on a case-by-case basis
  • Irrigation weaned off earlier during forest establishment