Here's a very rough diagram of the difference in Crit's back from that of our normal females.
There's a water Onion, and some green wendtii in there. the rest are plastic except the orange one, that one is silk. I don't worry about plastic plants around the girls, their fins are shorter and less prone to tearing than say a VT male or HM male.
I went to walmart, Meijer (a Great Lakes regional store) and pet supplies plus when they were having a sale on plastic plants and spent probably a good $40 on fake foliage. Our females aren't nearly as stressed anymore.