Potting soil is OK as long as it doesn't have the little white fertilizer stuff in it (dragons like to eat those). As far as safe plants are concerned there are too many to list here but go here: http://www.triciaswaterdragon.com/mischerp.htm#toxic and this list will lead you to places that list toxic plants. Also, that is probably the best WD keeping site on the net. I use Pothos, Ficus, and Dracena in my viv. They seem to love the taller plants but kill them quickly by climbing on them... Hope this helps!!!