I collected some cedar elms a few years back. One had a good root system and the other barely anything but a few long roots with virtually no fine roots. When the following Spring came I repotted the one that had the good root system in a free draining mostly inorganic mix as most everyone advises to do because this kind of mix will help develop a finer root system. But on the other tree, for fear of damaging the few roots on it, I left it in the native heavy red clay soil it was growing in when I collected it. So come the following season the tree in the native soil had more than twice the growth rate that the one in the free draining soil had. Now its roots are probably long and gangly, but its growth has really been much much better. I mean this is the soil in which these type of trees are found growing like weeds. There has to be something in it that they like. So my question is if a tree thrives normally in a region where the soil is heavy and compact, does it make since that if you were more concerned with rapid growth rather than fine root development to use the native soil or am I missing something?