I have tried every soil ingredient under the sun, even some that people have never heard of. I used to have a strange obsession with soil components, I had to try everything, every species of tree/ cactus/ orchid/ etc. went into its own customized (sifted to size according to species, inorganic/Organic fractionalized according to species) soil mix. After a while I just realized I was making things ridiculously complicated. Now- For all my trees I start with a basic 111 mix of turface mvp- sifted over a 1/8 inch screen, "reptibark" fir bark- sifted over a 1/4 inch screen then sifted over a 1/8 inch screen, and "manapro chicken grit" crushed granite sifted over a 1/4 inch screen then sifted over a 1/8 inch screen. I adjust the turface and granite fractions for conifers but always keep the fir bark at no more than 1/3rd of the overall mix. I always rinse my components thoroughly with r/o water after sifting and before mixing. This mix never fails to hold it's structure until the next repot and that is what matters to me, there a many other ingredients i could substitute to get the same results but these are easy for me to find. If I didn't sift I would have way too much water retention and the roots would suffocate. If I used composted bark it would break down to quickly and fail to hold it's structure until the next repot. I water using only r/o water that has foliage pro 936 diluted into it at 1.25 ml per gallon and I flush the pots every once in a while to rid myself of mineral buildup however under these conditions it's usually not a problem.
