plant suggestions: tangled roots

["Roxanne Bittman" <rbittman at dfg_ca.gov>]

I think most "stem plants" have this problem.  There is always going to
be some maintenance required with these plants involving trimming and,
after awhile, pulling/cutting/and replanting.  If you don't like this
answer, you could consider plants that don't need trimming at all: 
aponogetons, cryptocorynes, vallisneria, sagittaria, crinum, etc.  But,
even these finally grow too crowded in time and need to be thinned.
Roxanne Bittman