Understanding fertilizer and break down from the yamadori video

Context of question :
I was watching the yamadori video with ryan and randy.
What I took from it is yamadori trees do better with a miracle grow tip fertilizer every ten days. With time release?
The question. Ryan said something that caught my attention and asking for clarification. Does biogold not work on pumice yamadori? Or will it eventually work due to the football having the bacteria?
If it actually works but works a lot slower being pumice, is it beneficial to have the biogold on there and hit every ten days still with a miracle grow for 1 year old or so yamadori?

Looking for great dialogue on this.

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My take:

I don’t think it’s a yamadori, per se, but that they are planted in mostly pumice (with some field soil). Pumice keeps its shape and keeps water spaces. It also grows coarser roots. For this, any fertilizer is okay. Biogold, at this point, is just more expensive and has lower NPK ratings.

Once you start refining the tree and using akadama, whether 1:1:1, 3:1:1 or 100%, you should start using more organic fertilizer. Chemical fertilizers tend to be really hard on the microbiome in the container, and doesn’t allow the bacteria and fungi to flourish. The microbiome is also part of what helps the soil keep structure and not turn into a muddy mess.

And with a lot of things, there are tradeoffs between the different approaches.

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So for my planter trees keep the biogold per say

New trees in pumice are you saying stick to the teabag and biogold or better to switch to the miracle grow 20-20-20 as Randy does it until it’s potted?

Or doesn’t matter?

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I use bio-gold for everything. :man_shrugging:t4: Well, not totally true. For my field growing plants I use osmocote. Someone once told me that using things like miracle-grow results in crackhead trees that get addicted to the stuff. Ever since then I’ve shied away from using the stuff in my outdoor plants. I do use miracle-grow sticks for my indoor plants though.


I don’t deal with recently collected trees, so I can’t really speak too much on that with direct experience. A 20-20-20 will make it push a lot of coarse growth while it’s recovering (but don’t do it too soon, as you could overly stress a weak tree). That can be a good thing based on your developmental goals. The organic fertilizers will be good for building a microbiome, but you won’t get the same growth response. And a lot of that may fall off once you repot into a bonsai container.

I think chemical fertilizers can be beneficial in short sprints for specific purposes.


I’m sure they can be. Nigel Saunders grows his willow bonsai in tubs of water with 20-20-20 in it. I believe Walter Pall also regularly uses chemical ferts. Dennis Vojtilla mentioned using them in the past.