Akadama + Pumice (but no lava rock)

Beginners
1

Hi, I live in Korea. Large bags of Akadama (differeent sizes) and Hyuga Pumice (differeent sizes) arrived today. I could not find lava rock.

Will Akadama + Pumice work ok as a mix?

Thanks for all of the help!

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2

What kind of trees are you growing? Confier, deciduous? Shohin, chuhin, ogata?

For what it’s worth, I’ve grown trees in pure akadama, pure pumice and a 50/50 mix of akadama and pumice (as well as standard 1:1:1 akadama, pumice, lava mix). They all survived (or at least, it wasn’t the soil that was what killed them).

The soil mix will work but you will have to adjust your watering, since both akadama and pumice hold onto moisture.

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3

I’ve successfully used a 1/3 mix of --1/4" chicken grit (re: granit). Drains well, better for dryer roots loving trees.
I have access to red lava rock by the ton, though, and use it for the porosity and water retention in mix.
.
THE problem… I can’t grow moss AT ALL without a top derssing… AGAIN, adding organic material to the mix…
and I love my moss…

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4

The lava is to provide space for oxygen. If you’re growing deciduous trees then you’re good to go. It basically boils down to this:
Akadama is for CEC (cation exchange capacity) aka more readily releases nutrients to the roots
Pumice is for water retention
Lava is for oxygen balance as it will typically drain the water out quickly and provide gaps for oxygen

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5

Thanks a ton! I am going to give it a try! I might add a few larger pumice pieces to the mix to help with oxygen flow. Thanks again!

6

You should add an aeration layer at the bottom of the container which is large particles. Check the nursery stock repotting video.

https://live.bonsaimirai.com/library/video/rootbound-nursery-stock-repotting

7

Thanks a ton for this video, watched it all, it was great!

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