Hi Alex. A dieffenbachia or spotted dumbcane (silly name huh?) can grow as tall as 6 ft. They are beautiful. I see you also posted something about a Norfolk Island Pine. Mine grew to nearly 7 ft and I was forced to give it away. They like cooler temperatures so near a window or large pane where it receives bright light is perfect. Two great
plants ... you're so lucky! The browning could be a need for more humidity.
http://www.thegardenhelper.com/norfolk.html this article has some great stuff. Andi