Could you talk about best soil for post collection yamadori? I think i noticed 100% pumice in one of your videos. Incase i missed why could you elaborate was that species specific or because of the high water retention of pumice? or just stick with 1-1-1 pumice-lava-akadama?
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This is the video. It is not species specific.
live.bonsaimirai.com/archive/video/post-collection-potting
The why is balance of h2o & o2. Collected material generally has less roots and thus needs less water and more air. This is why pumice is ideal. It holds less available water and provides good airflow so new roots can emerge. Collected material knows that it is in a critical state and will redirect resources to keep itself alive, growing below the soil line to do so.
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aah pumice promotes o2 and holds less water thank you.
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…and best to let the collected tree sit for at least 1 full year. This allows the tree to recover, and it helps you to understand what the tree likes / doesn’t like…which is important for the tree-health.
New trees are sometimes like our kids…each is different, so each demands “special” attention!
Cheers…
Flex
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Is it important to sift the pumice? Should you leave in the dust or the sand particles? The smaller particles would hold more water (and less air) than the larger ones. By keeping both fines and larger particles might allow more variety in the soil for roots to find their best balance. Any experience out there?
Sorry folks, that was addressed in the repotting stream. It is recommended to remove the fines as well as the 1/16 to 1/8 bits. Use only the screened 1/8 to 1/4 mix. Now I start to sift a lot. I still would like to hear if there is any experiences about this out there. Thanks.
Definitely sift your soils, pumice, akadama, lava, any organic parts of your mixture. The 1/8”and less particles of pumice aren’t free draining, which will create a sandy paste when it is saturated, not good for the health of the tree.
I got a yard of pumice last year and sifted almost a garbage can full of 1/8” to dust. It all depends on your source, being bulk will create more unusable particles and bagged will have far less. 
I collected two trees last year and planted in a mix of 50% DE / 25% lava / 25% perlite and got excellent root growth and foliage growth.
Could I expect even better performance with straight pumice?
Pumice will perform the best because we want a healthy tree first. Pumice is an ideal environment for root growth creating the balance of water an oxygen, retaining heat and holding nutrients and water in its microscopic pores. If you have seen any of the collectors here in the states, @BackcountryDan @Todd_Schlafer and others, they use 100% pumice.
Since you have great root and foliage growth, the tree is obviously happy.
Some pics would be great 
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I’ll give that a try this year. I’m always open to even better results.
My trees are frozen into their mulch right now but I’ll try to remember to come back and post pics when they thaw out in April or so. lol.
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Did you ever try to cultivate it in pure pelite ? I dont have any Lava ore similar things left and would like to plant my colected trees in pure perlite. Does anyone know if this is an good idea
Personally, I don’t like perlite because it floats and it seems to lock together tight, hindering the ability to drain freely.
Some people use perlite it in the bonsai world.
I feel pumice is a superior substrate to perlite
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Guess I will get my self some pumice 
thanks!
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