Mychorysal fungi is present whether the soil is organic or inorganic.. I have no preference either way, but it happens to be that Akadama is inorganic.
I have used different soils but I always come back to Akadama. It is not cheap as it once was, but that's the way it is.
I know guys who use a mixture of loam and composted bark, others add pumice. As I said before it is a personal choice, and most soils are good in their own way. Depending on your situation will dictate what kind of water retention you need. One friend of mine used a soil mix which for me was no good at all, but he needed a soil that held more water all day.
So use what is best for you and not other growers,
Geoff.

akadama can be found in the us .I live in the north east and haven't spent more than 40$ on a 5 gallon bag. akadama also comes in different hardnesses from soft to very hard ...soft = more water retention but faster deteriation , the harder the less of the 2.

In my club a number of members have moved to expanded / baked clay as is found in certain kitten litter products. They seem to be completely invulnerable to heat/cold, having survive 5+ years with some members without any detoriation at all. It holds water well. The downside to acadama would be that it is possible less good at ionic exchange, but I have not seen any research into that.

I add pine bark to my pots; I am a lazy bugger and only water my plants every other day, unless we have extreme weather (Like today, with temps going to 100F/37 celcius, which is abnormal here).

i have used speedy dry (calcined clay) which is a backed material for cleaning spills.i have used it in a mix at 30%and it seems to hold too much water during rainy spells.akadama and bark are known for their ability to retain nurtrients. calcined clay i do not know...

yes jelle the weather is weird here too. we are usually dealing with 90F/32C+ weather ...we will be lucky to hit 60F/16C this sunday

I have been warned not to respond to posts so late after topic but I feel this will be admissible. Of all the research and reading I have done, I remember hearing from many people the fact that Bonsai soil is not really soil at all, your situation does need some specific conditions for sure. I have learned that root rot is a big concern for mostly organic soils.

This thread is a mere 2 weeks old. Don't worry. You're fine

As for which soil to use.. Every bonsai grower has his/her ideal mix. meaning.. It does not really exist

Hi, my name is Sagir, I am so new to this amazing world of Bonsai Trees, I was given a Juniper Bonsai Tree for my birthday. I really love it and as far as I know, I have followed the instructions it came with for taking care of it, unfortunatley it seems like it's diying, I am thinking about repotting it, but I haven't been successful at finding the correct mix where I live (Magnoli TX) Could you share with me a good source where I can get this combination (Kiryu and Akadama) you mentioned has worked for you? I am fasinated with my tree and I would really hate to have it die. Any help will be greatly apprecitated Thank you in advance!!!

Sagir,

welcome to the forum. On this forum we prefer it ig you make your own thread for questions.
Just a shorty anwer, more in depth once you have your own thread: Do not repot if the plant is not fully healthy. Repotting is NOT a cure-all solution. Figure out why the plant is dying instead.

Does anyone repot their shimpaku junipers in slightly acidic substrate? maybe 1:1:1 lava.acidic calcined clay or kanuma and pumice.

I'm in Southern Arizona in the U.S. and I'm going to be trying equal parts bark, pumice and lava rock on my trees this year. I've been using a mix of lava, gravel, and potting soil, but the potting soil is settling at the bottom of the pot, and the gravel doesn't really add anything good to the mix.

I think that by going with the new mix, I'll have the bark for water retention and CEC, the pumice for water retention, and the lava rock for drainage and air. I'll be adding some moss on top to help keep everything from drying out too quickly as well.

Hoping to put one of my junipers in this mix in the next few months, to get it out of the muck it's in. My water is also really hard, and I'm hoping that the slightly acidic bark will help.