You use that mix for the jade (the dry one), but for the rain tree, use a slightly larger proportion of organics... learn when to water and do it well when you do. Better to water more often than necessary, knowing it'll run through and not rot roots, than to water and have the soil stay sodden forever. It's not easy to 'get', but that's part of the game :).

Hello db,

I have been researching bonsai "soil" for nearly a year now. I am finally ready to mix my materials in the next few weeks.

Purely by chance, I stumbled across some invaluable information on this site. If you are just starting to learn about soils, I believe this info will help you understand, the concept behind well draining soils.

Bonsai soil (especially) needs to be very well draining, that's why there aren't any fine materials in it.

Don't be discouraged by the amount of reading this involves, there are some (guide line) soil mix recipe's towards the end.

click me- [https://www.houzz.com/discussions/container-soils-water-movement-and-retention-xxii-dsvw-vd~2842847[(https://www.houzz.com/discussions/container-soils-water-movement-and-retention-xxii-dsvw-vd~2842847)

I would imagine however, that you would like to re-pot fairly soon.

Hoffman Bonsai soil isn't bad for a pre-mix, just be sure to remove dust, run it through a metal mesh kitchen strainer or insect screen.

I've seen it for sale online or at some nurseries.

Good luck.

Rob

In short deepbonsai, do not use "potting soil".

Examples of some materials you could use: Turface MVP, insoluble crushed granite, Haydite, scoria, pine bark fines, D.E (Diatomaceous Earth)., pumice etc...

You want around 1/8 inch particle size (ideally).

You need to figure out, what the water retentive properties are for the materials you're using.

For example, Turface & Haydite both, are very porous & hold onto a lot of water.

This is a very interesting subject. There are a lot of people here, more than willing to answer your questions.

Rob

Turface & haydite do NOT hold onto a lot of water because they're porous - water runs through them more easily than potting soil.

thank you moochinka and halocline. I thought about using a premix and I still might but I the end I want I'm seeking the knowledge. I will be sure to read the link thanks brandon

"The Merriam-Webster Dictionary- 'porous: absorptive-porosity',' absorption: a process of absorbing or being absorbed' 'absorb: to suck up or take in in the manner of a sponge"

Turface and Haydite, are both water retentive materials, more so with Turface.

moochinka,

do you currently have in your possession, both Haydite and Turface in 1/4-1/8 inch blends?

I do.

Are you currently growing two similar trees of the same family, one in a Turface mix, and one in a Haydite mix?

I am.

(Purely for experimental purposes.)

Oh, and, I never said, Turface & Haydite hold onto a lot of water because they're porous. But... That is correct.

Rob

In my beginings with bonsai I killed a lot of Japan maples unlearning what I thought I knew. The critical part of the artificial soils used isn't how well they hold on to moisture. Rather it is how well they admit air.

The use or organic fines or loess soil is exactly what your trees do not need. Oh you may be liable to water more frequently in the hight of summer, but without the air that a 50-50 mix of oh, say gran-i-grit and pine bark mulch supplies, your trees will drown.

Coppice - I think you're on the right track with the air:water thing; but first: Turface holds a lot of water compared to perlite or Haydite, this due to its porosity and it's tremendous surface area (13 acres per pound of Turface according to their website). Haydite holds some water internally in pores and on the surface of the particles. Perlite holds all of it's water on its irregular surface.

Envision the perfect soil - what would it be? I think the perfect soil would hold all of its water (enough to keep the plant and grower happy) on the surface of particles, within particles in small pores (like little sponges), and at the interface where particles contact each other, leaving ALL the spaces between soil particles filled with air only (because if they're filled with water, the roots are starved for air and can't function normally). It would also be a very big plus if we could adjust how much water a soil holds without having to infringe on the air space that is so important to root health. As a side note, I'll suggest that getting nutrition to our trees is so easy, there is no need to depend on the materials we build our soils from to provide anything in the way of nutrients.

Anyone not agree so far? If there is disagreement, please describe your ideal soil.

Al