[@Leotamer] - Indeed. Poisonous or not the metals were not going to be slowing down it's growth. What amount Ferron was able to put into the tree was diluted to the point where it's presence inside the roots weren't even noticeable for all who aren't inherently in tune with metal. Even Ferron himself would find it difficult to pick up the minute traces that remain once they run their course in the growth of the surrounding plants.