Potting Mix Tests Results Abbreviated

[Paul W]

[Grant Bowie]

Hi, I retired as the Curator 4 years ago and I believe the mix has not changed substantially at the NBPCA. At the collection we have 2 staff and many volunteers to look after the bonsai.

I do add about 10% of a fine or slightly bigger Akadama to my own mix these days to aid with moisture retention but not get too wet.

Everyone has to decide their own mix based apon location, geography, frequent fertilising or not, frequent repotting or not, full sun or heavy shade , retired or working, etc etc etc. so I will not try to give detailed advice.

I believe if you read the entire thread it will give some clues and all input and experiences are welcome.

I am currently in Japan and just made Nagoya after 2 days in Tokoname.

Grant

[Grant Bowie]

Hi all, I was about to restart this thread and I noticed my last post was 4 days before my almost fatal heart attack, hence the lack of input for the last 5 1/2 years.


Hi all, It’s about time to put some more info here. I haven’t looked at these tests for many years now and do not intend to pick up where left off, but rather to talk about materials that have disappeared from availability, some new ones and current usage of materials of my own Bonsai.

Firstly, Maidenwell seems to have disappeared from the market, which is a great pity.

Anybody have any updates on Maidenwell. Please post here.

Grant

[dansai]

Another component that would be interesting to gauge would be Sakadama - the South African "Akadama" that is fired to 600degC. It seems to be readily available throughout the world ATM, but has had little field trials to show how it preforms over a period of time. I have just reread this entire thread and noticed Grant that you mentioned Chinese Akadama as been fired in an early post. It did not preform well on is own and it broke down readily. My understanding of the Sakadama is that it should resist breaking down due to the firing, but may not provide the reputed advantage of Akadama of breaking down slowly through root action that leads to root ramification.

I also noted that Akadama didn't give any advantage in the tests you did, yet it is highly recommended by various enthusiasts and professionals (mostly overseas). I know there is a few grades of Akadama that would preform differently in different climates.

Another thing Id be curious to know is if the NBPCA has altered the mix in the last few years? It was my understanding that Akadama had been incorporated in the mix and now they are using Sakadama due to the difficulty of getting quality Akadama.

[melbrackstone]

I'm trying to re-read it too, keep getting sidetracked. One thing I will say, the ability of Akadama to produce lots of ramified roots is proving to be correct, since every weed I've pulled out of the plants potted in pure Akadama have the most amazing root systems, twos into fours into eights etc. Usually the majority of the oxalis root system is quite simple....

Next year I'll be repotting some of the trees planted into 100% Akadama, so will know more then.

Looking forward to seeing more on this thread.

[dansai]

Another thing worth considering is what it is you are trying to achieve with your mix. Grant, you made a mention at some point that moderate growth could be acceptable as it would provide shorter internodes and leaves. The tests you did compared growth rates and those that were considered as preforming well were those that produced more growth. This may be an advantage when developing stock, but the slower growth would be an advantage for established trees in refinement. The advantages of Boons mix (Akadama/pumice/scoria) which I understand is used in some Japanese nurseries is the slow growth, fine roots and good longevity of the central root mass.

[treeman]

Another component that would be interesting to gauge would be Sakadama - the South African "Akadama" that is fired to 600degC. It seems to be readily available throughout the world ATM, but has had little field trials to show how it preforms over a period of time. I have just reread this entire thread and noticed Grant that you mentioned Chinese Akadama as been fired in an early post. It did not preform well on is own and it broke down readily. My understanding of the Sakadama is that it should resist breaking down due to the firing, but may not provide the reputed advantage of Akadama of breaking down slowly through root action that leads to root ramification.

I also noted that Akadama didn't give any advantage in the tests you did, yet it is highly recommended by various enthusiasts and professionals (mostly overseas). I know there is a few grades of Akadama that would preform differently in different climates.

Another thing Id be curious to know is if the NBPCA has altered the mix in the last few years? It was my understanding that Akadama had been incorporated in the mix and now they are using Sakadama due to the difficulty of getting quality Akadama.

Sakadama is certainly not comparable with akadama. It has a very high pH (pH (9 -10!, at least the one I have tested. The bag says neutral ) so you have to allow for that. Washing might help?? I'm sure it will have it's uses but it is basically like expensive scoria. I intend to use it on my cacti.