One magazine which has not been mentioned is Garden Railways. It is another Kalmbach publication, and as the name implies is devoted to garden railroading. It contains considerable coverage of flora related issues. Being gardening challenged (I have been known to kill a rock)I find this aspect of minimal personal interest.
It is primarily aimed at the "toy trainer" and not the scale modeler, although Marc Horovitz is pretty hard core. Garden Railways was originally Marc's magazine, but when Kalmbach bought him out, they are calling the shots. It's pretty apparent that Kalmbach does want anything in GR which interferes with Model Railroading's turf. Garden Railways has the largest circulation amongst magazines devoted to large scale model railroading.
As an aside, when GR became a Kalmbach publication, they immediately reduced the size of the format, cheapened the paper quality, and raised the ad rates by a very substantial amount.
CJ