Someone with more info correct me if I'm wrong, but, ime, the standard
cattail gets about 6 ft. tall with a catkin of ~6", then there's a dwarf
that is 3 ft. tall and catkin 2-3" and miniatures are only 18" tall with a
catkin less than 1". ~ jan

I have cattails, not sure if the are miniature or not. Last year they were
in 18 inches of water in my VF, and did OK. I recently repotted them, and
sank the pot in about 3 feet of water. I already have 3 new shoots breaking
the surface. BV

~ jan (Do you know where your water quality is?)