That's true, also in reading further, they're invasive and need lots of moisture, they love bogs...so now I'm not really that interested either! I have shade but its not boggy or even very wet, in the summer unless I water. Now I have to figure out who I know has a pond
and give them this but tell them to plant in a pot! (although one comment on the link you shared, said that the rhizomes can grow out of the drainage holes
I guess if they like boggy, one doesn't need to have drainage holes at all