Hi all, I would like to know about the wisdom of using greensand in potting mixes or as a top dressing as a source of potassium and trace minerals. I read that it weathers quickly making the various minerals easily available to plants. I have used it in the vegetable garden for some years, especially on root crops, with success that cannot be directly related to greensand. I think that it is a good, "kind" source of potassium, but I am wondering to what extent the trace elements are available. Dell, in SE Pennsylvania, USA, Zone 6/7