The Miyawaki method grows a small native forest fast. You plant many native species close together on loose, well-fed soil, then look after them closely for about three years. This is our short guide to it, and what it would mean on our planting pilot.

  1. 1SurveyFind what grows wild within about 20 km.
  2. 2Choose20 to 40 native species, four layers.
  3. 3SoilLoosen 60–100 cm deep and feed it.
  4. 4PlantAbout 3 per m², mixed, never two alike side by side.
  5. 5Stake and mulchA stake for each sapling, straw over the ground.
  6. 6Care, then let goWater for three years, then leave it.

Four layers

A natural forest grows in layers. The method plants all of them at once.

Side view of a forest in four layers: canopy, sub-canopy, understorey and shrubs, with their heights. 03 m6 m12 m20 m+ Canopy · 40%12–20 m+the top of the forestSub-canopy · 30%6–12 mshade under the topUnderstorey · 20%3–6 mflowers, fruit, birdsShrubs · 10%1–3 mcover near the ground
  • Canopy40%
  • Sub-canopy30%
  • Understorey20%
  • Shrubs10%

In our pilot: 8,000 · 6,000 · 4,000 · 2,000

Share of saplings in each layer, and how tall each grows.

Use 20 to 40 species that grow wild nearby. The guides' examples, such as oak, ash and beech, come from cooler countries. Ours will be native trees of this part of Cambodia, chosen with nurseries.

Soil first

Roots go down fast in loose soil and spread sideways in hard soil. So the ground is dug and loosened deep before anything is planted.

Cross-section of the planting bed: mulch, a low mound, loosened soil 60 to 100 cm deep with roots going down, and hard subsoil below. Mulch10–15 cm Low mound15 cm high old ground level Loosened,enriched soil60–100 cm Hard subsoil

Mixed in, per m²

  • Husk or straw4–5 kgkeeps air in the soil
  • Coco peat or biochar4–5 kgholds water
  • Compost or old manure3–5 kgslow food
  • Leaf mould or neem cake0.5–1 kgkeeps pests down

Close and mixed

Planted close, young trees compete for light and grow up fast. The guides give about three per square metre, or 50 to 80 cm apart. Saplings go in at 60–80 cm tall, after a few months to a year in pots.

Top view of a 4 m by 2 m patch with 24 saplings in four layers, rows 0.50 m apart and trees 0.67 m apart in a row. 0.67 m 0.50 m 1 m² box · 3 per m²
  • Canopy10
  • Sub-canopy7
  • Understorey5
  • Shrub2
Never two of the same species, or the same layer, side by side.

Stake and mulch

Tie each sapling to a stake so the wind cannot rock its roots. Then cover all the ground with mulch. It keeps the soil damp, feeds it slowly and keeps weeds down.

Care, then let go

  1. Year 1Water every day, about 5 litres per m². Weed by hand. Keep the mulch on.
  2. Year 2Water 2–3 times a week in dry spells. Top up thin mulch.
  3. Year 3Water only in an emergency. Watch how it grows.
  4. AfterLeave it. No water, no fertiliser, no pruning. Leaves stay where they fall.

On our landEvery dry season: clear the firebreaks.

The guides say the forest looks after itself after about three years. On our land the firebreaks will still need clearing every dry season.

At our scale

The pilot plans about 6,700 m² of planted ground and 20,000 saplings. Here is roughly what the guides' numbers add up to.

  • 20,000saplings
  • 20,000stakes
  • 77–107tonnes of soil additives (11.5–16 kg per m²)
  • 670–1,000m³ of mulch (10–15 cm deep)
  • 33,000litres of water a day, in the first year (5 L per m²)
Rough figures from the guides' rates. They show the size of the work, not a price.

The pilot budget covers the saplings. Everything else in these tiles still has to be worked out. Water stands out: we do not yet know where 33,000 litres a day would come from in March and April.

Where we will do things differently

The guidesAbout 3 per m².

Our planTest 2, 3 and 4 per m² side by side.

The guidesExample trees such as oak, ash and beech.

Our planNative trees of this part of Cambodia.

The guides10–15 cm of dry mulch over everything.

Our planRethink it. Dry mulch can carry a fire. Ask about thinner layers, other materials and wider firebreaks.

The guidesAfter three years, leave it alone. Never prune.

Our planClear firebreaks every year. Maybe a small trial of moving young trees out of the densest plot.

The guidesGrows 10× faster, 30× denser, 100× more life.

Our planNot measured here yet. We will publish our own numbers.

Both guides agree that the method costs more at the start than ordinary planting and needs water that reaches every tree. One is a guide from SpiceTree Munnar, a farm stay in Kerala that has planted with the method. The other is a short field guide shared with us.

The pilot page has our plot layout, how to mark it out, and what we will measure. We will write again when the species list and the water plan are settled.