FredL

Ron, from my own experience, nothing will prevent drastic overwatering or underwatering from damaging or eventually killing a tree. Good soil will, however, greatly extend the limits of what costitutes sufficient watering. Understanding the physical structure of good bonsai soil is simple enough: it simply has to permit rapid draining of water between the soil particles and retain water within them.

Now, how to attain that blessed state.......there's the issue!

Fred