Inorganic soil questions...

I am getting ready to build my own training boxes (24x24x8) and I would like to use inorganic soil for the trees I put in them. Tell me if I have this part right, this inorganic soil needs to have good drainage, hold moisture (not water though), and will not compact (so air can get to roots). Could one use old concrete or bricks for this if you cleaned them up?

To start I want to make 10 of these boxes then when I move to the country I want to make a lot more. Since I will be needing a ton of inorganic soil I am looking to find some cheap way of getting this organic soil and I know a guy that will give me all the old building material I want. I just do not want to pay the prices online plus the shipping cost of all this soil.

Herby, I'm not sure I understand what you mean by "inorganic soil". Could you explain that please?

Soil that does not contain any material that was once living (animal or plant) but instead is made up of different types of rocks (lava, terface, perlite, ect.)

I have heard of this for hydroponic gardening but I've never heard of it for in-ground planting. Do you have some plan to keep the material wet constantly? If not, the tree roots will dry out and die.

katiebear

You water the tree twice daily...

http://www.bonsai4me.com/Basics/Basics_Soils.html

Are you doing bonsai or do you plan to use this method with full-size trees?

kb

I think the crumbled bricks would be safe so long as they are originally clay brick and not concrete bricks. But if I understand correctly the cement would be bad because it leaches something (lye?) that would not be good for the trees.

Will these be outside in freezing weather? If so, that might be a problem.

kb

In Bonsai if the roots can grow out instead of down then it helps fatten the trunks up faster thus the size of the "boxes". I plan to let all the trees grow to around 5-10 feet depending on the size of the trunks then start to cut them back to work on the tapper.

In the winter I plan to keep the trees in the unheated basement since it gets only to about 40 down there. That should give them the cold they need but not the freezing cold like it gets in my area.

Not that I think about it I think cement does have lye in it... But clay brick I can get all day long for free. I just need to find a way to get them broke down to workable size, I am not about to start taking a sledge hammer to them all.

I did the math...
24x24x8 box can hold 19.9 gallons of liquid...
since I want to have some air space in there I will go with 15 gallons of soil each...
Online I found 10 quarts of fired clay for $17...
For 10 boxes that is 750 quarts...
$1200+...
plus shipping and handling I would have to call to get that...
so bricks are the way to go if I can crush them into small bits...

You might want to think about clay cat litter. The cheap kind. Very absorbent, holds moisture...Mixed with the brick it just might give you a good and affordable inorganic mix.