So I'm looking at mixing up some bonsai soil but unfortunately I have to make due with what I can get my hands on at the moment.

Basically my ingredients I'm looking at are:
Small cinder rock
Pumice
Small granite chips
Charcoal
Small orchid bark
Perlite

I'm just not sure what would be the right ratio for both conifers (junipers and pines) and for deciduous trees (ficus and fruit trees). Any help would be great! Thank you

all you need is Akadama , pumice, Kanuma, horticulel grit and bark, mix will depend on the type of tree. 40% hard akadama is a good base point

I can't find nor afford to order akadama so I'm having to work with these ingredients alone save for some sand

you need some thing with a good cation exchange capacity and there's nowt in that list that would do, clay fired cat litter has been know to be used but is not advisable if you don't know what your doing and teasing for because there all different and some are highly alkaline. or have a look in to something at the hydroponics shop. but at the end of the day your trees will only be as good as the soil you use.

I should also mention that I need something that will hold enough water so I don't have to wait on my trees hand and foot. A full time job and other responsibilities unfortunately don't alow me to spend as much time with my trees as I would like. Thanks!

sphagnum moss

True...

It does not really matter what you use, and yes. I know. I am contradicting an other member here. Fired clay that is sold als kitty litter works very well, but stay wet a long time.

Main things you need:
- Good drainage: So sift whatever you use to be at least 1-2mm in size
- Ability to retain moisture fo some time (Your bark would work well)
- Be able to warm up reasonably well (So I would not use granite)

I would probably go for pumice (How big are the granules?) with bark based on what you say you have abailable.

The pumice is about 1/8 to 1/4 inch (sorry not sure what that would be metric) and about the same for the bark. I'm definitely planning on sifting it but you think the two would be good on their own? I am kinda avoiding using clay.

What would be your suggestion for the ratio?

Also as a side note, would charcoal ever be a good idea? Just out of curiosity.

Brookings wrote:

The pumice is about 1/8 to 1/4 inch (sorry not sure what that would be metric) and about the same for the bark.

There's an easy trick for that: Google it. Just type in " 1/8 inch in cm " and you'll get the result:

(1/8 ) inch =
0,3175 cm