Water lilies can spread from seeds or the rhizomes. And mine has definitely spread. At first I had it in the pond in its pot, but the dog kept pulling the pot out of the water and chewing on the rootballs. So I took it out of the pot and let it naturalize. It's been in there for years and blooms more each year.
Today we cut a chunk of the rhizome off for my neighbor who is putting in a pond. I wasn't sure how it would go, but, I'm not worried anymore.
