Akadama

Akadama is in fact a form of volcanic soil (Pumice) mined exclusively in Japan and has excellent properties for plant growth. Akadama is light in weight and therefore easier for pot handling, but most importantly they have the following useful properties:

1. They drain perfectly if prepared correctly (see below).
2. They allow air to be drawn into the mix when watered.
3. They maintain near perfect moisture retention for plant health.
4. They are granular in character and aid root/nebari development.
5. Allow greater control over fertilisers in the potting medium.

Akadama is Neutral in PH so is very safe to use on all plant types.

The Akadama used for bonsai potting purposes in Australia is HARD Akadama, and comes in 4 grades or grain size:
1. Akadama Large 12-21mm – 14L Bag (Used mainly for drainage layers in larger pots)
2. Akadama Medium 6-12mm – 14L Bag ( for larger trees and pots)
3. Akadama Small 2-6mm – 14L Bag (for use in most sized pots and trees)
4. Akadama SuperSmall 2-4mm – 14L Bag (Used mainly for cuttings and smaller bonsai such as Shohin & Mame.)

In using Akadama, it is advised to follow the repotting system recommended by all Japanese Bonsai Masters and Growers:
The first (bottom) layer is large (drainage) then 50/50 of medium and fine grade (depending on size of your Bonsai) for the remainder of pot. If this is adopted the resulting growth, particularly in the second year after repotting, is strong yet controllable.

The Super Fine Grades of Akadama and Kanuma can be used for cuttings, either combined many differnet other componenets with River/Propagating Sand 50/50 or just use it Straight out of the bag.
I like to use a bleend of componenets in my trees, Equa
IMPORTANT: PLEASE NOTE
Akadama can be re-used several times, making them very economical (gently sieve them each time (removing dust) and water accordingly).

With Kanuma: After repotting, the pot should be watered copiously until the water runs out clear from the bottom of the pot. This ensures very little residue will form in the bottom of the bonsai pot.

SOIL: MIXES
In Japan it rains for the month of June (Northern hemisphere) and the temperature is about 30°C; July is around 35°C with about 99% humidity. These mixes have worked very well in Japan for 100 yrs or so and if used correctly achieve wonderful results.
We recommend you experiment with different mixes to ensure the best growing medium for your growing conditions/environment.

HARD AKADAMA (neutral pH):
Used for Coniferous, deciduous and all other varieties, except acid-loving plants.
Black Pine/White Pine/Shimpaku: Akadama 7 parts, Coarse River Sand (CRS) 3 parts.
Red Pine: (1) Akadama 6 parts, CRS 2 parts, Japanese Black Soil or Coco Peat 2 parts. (Ordinary peat repels water if it dries out in the mix.)
Or:
(2) Akadama 8 parts, CRS 2 parts.

Zelkova/Elms: Akadama 8 parts, CRS 2 parts.
Maples: Akadama 8 parts, Sphagnum Moss 1 part, CRS 1 part.
Ficus: 100% Akadama

Australian Natives: This is currently an open field but Akadama has been used 100% on its own, mixed with Kanuma and/or Pumice and other media with remarkably good effect. Very strong healthy growth and good flower production have been recorded to date.

NOTES:
Sphagnum Moss should be prepared by drying and then rubbing through a medium sieve to make even particles before adding to the mix.
If using River or Propagating Sand, sieve out the finest particles. Small gravel of a uniform/graded size could be used instead.
When repotting do not jab too hard with the chopstick as this will break the granules down. Once the potting medium has been lightly jabbed with chopsticks, tap all sides of the pot to encourage further settling of the potting medium.
Large particles produce heavy root and heavy top growth while fine particles produce fine roots and fine top growth - important for pines in particular and any bonsai once the basic structure is established.

Following these simple instructions a perfect very open free-draining mix can be achieved - ideal for bonsai culture.