In all seriousness it's the same as using sand but a larger particle size. Holds very little water and could be a good compliment to something like turface that is alleged to hold a lot of water. Just my non scientific opinion. Interested in hearing whether it makes any sense to you Al or am I thinking of it arse backwards?
I am just trying to get a handle on people that wish to add rock to their soil mix. A plants roots need two things to grow and THRIVE. They are water and AIR.
Those two words are capitalized for a reason. Since the particle size is small on turface and can can lead to parched water tables, it seems that its moisture retentive properties are what people are looking for. Moisture retentive as far as a clay particle not because its undersized for a bonsai particle.
So in theory to get away from the parched water table due to it being so small, it makes sense in some eyes to add a larger more readily available larger particle like granite grit that can be had at feed stores and pet stores.
Could we also assume that granite grit might be a catch all term for any larger particle that could fill the bill by breaking up the small particles with larger ones mixed in? It would seem so. Even something as mundane as pea gravel? I see absolutley no difference in granite grit over pea gravel. In fact pea gravel would be better due to it being round which is better for less compaction and more gas exchange.
Pea gravel, who would be caught dead adding pea gravel to a bonsai mix? Is it more fashionable to use granite grit because it has been used in years past by big name bonsai people?
I might go out on a limb here and suggest lava to fill the void for the granite grit. That would be a natural correct? OK, so it seems that pumice and lava seem to be a product that is not readily available coast to coast at a reasonable price. The shipping is overwhelming. Why lava?
Lava is porous and also holds water like the turface. It holds it as vapor, which is what the roots need for exchange. So it seems to me that we need a product that is larger, holds some water for gas exchange and could be a hellava lot lighter and more advantages.
What about a mixture of Turface and No. 2 orchid bark. Not composted bark soil conditioner or things like that. Just bark nuggets and turface. No. 2 bark is about 1/4 inch, used for rooting orchids, and would be perfect for soil substrate. Orchid bark does not break down will not rob nitrogen since it is not decaying. It is just used for one thing, offering an oxygenated environment for orchid roots which need massive amounts of air and moisture as vapor.
Since turface seems to be readily available and orchid bark is available at all the big box stores as well as most local city nurseries, it seems that lots of experimenting could be going on. Wood as a soil option does not have to mean "OMG"
organic not for me. Ones pot could be at lest 30 percent lighter without the granite. Save that for the driveway!
Now, my big problem with this scenario. Using a larger particle with a smaller particle defeats the purpose of the larger particle in the first place. The smaller particles just get trapped between the nuggets and all the gas exchange is lost. I like soil that is screened for all the particles being the same size, that way no particle can get inbetween any other particle and the air exchange should continue all the way to the bottom of the pot.
So, those of you with no access to good soil components means you will have to work extra hard to get plants thriving. Thats all you can hope for. If you have never seen the effects of good soil before, this is all moot and means nothing to you. That is why Michael wrote the article. He comes at it from a point of view that he can get what he needs and therefore can rant to all of you that can't get it. Sorry......
