So I pulled them last week and got them planted. I planted one at 18", and one at 24". I'm hoping they get through winter, but if either makes it, my money's on the one buried 24". The pond's down around 2', so I'm thinking 3' to 4' down is about where they'll be during winter. They have excelled over summer, and I hope they do the same next year.

I like the cheap concrete tubs because they float ark like.
[Linked Image from i.imgur.com]

This one's settled in. I planted both plants inside the other hybrid lilies to protct them from grass carp. Historically, here at least, they munch on the plants easiest to get to.
[Linked Image from i.imgur.com]