Well, following some threads around, I have read some high respected people saying that root rotting because of overwatering is a myth. So, is this overwatering root rot really inexistent?
I should re-read these articles, but it is true. However, This concerns bonsai in proper, free draining soil.
When the soil does not drain and the roots stay submerged in water, they will not get oxygen and will die. This will give root rot a chance.
So, indeed overwatering itself does not directly cause root rot, it does cause roots to die and eventually rot. So, root rot is an indication of a problem with the roots, and that problem can be overwatering in non-draining soil.
I guess we often take the shortcut, do not tell the full story (again and again) and simply say the problem is overwatering. Which is not untrue. Usually the advice will be to use proper draining soil and water properly.
