Herman,
on this side, the taught agricultural mix is an approximation of a loam = sand - rotting stone - clay. About a dozen boxwoods were purchased and the trick was to get rid of that mix without killing the shrubs. Accidentally discovered was the effect compost had on the mix.It made the soil bead up and drain well, but you have to keep putting compost in ever so often,
Seems to to be a copying of what happens in the ground / fields.
Thus far, it may be that a simple mix of rounded gravel [ seen as the plastic coated stuff for aquariums from China ] and compost will grow anything, drain well and retain moisture.
So now the bonsai are growing in turquoise and or black gravel with compost, also seen is bright orange, but the line was drawn at shocking pink - ha ha ha
The real secret seems to be watering, how and when.
Good Day.
Anthony
The Hackberrys and Gingko are out of the refrigerator and budding well, there are also 4 apple trees some where in the batch as well.
Ah to be returning home ....................................
