JJ wrote:

Can one just place a weight on a Hardy Lily rhizome and simply place it in
2-3 feet of water in a man made pond that has a dirt bottom? Will it take
root and continue to grow? There is a pond in our neighborhood that could
use some foliage and everyone agrees that water lilies would be nice. The
pond already contains goldfish. The pound is aprox. 2 acres.
Any thoughts on how to plant?

That'll work fine. I've grown lilies bare root, just weighted down, for
years. They don't self-root, because I keep the pond bottom clean of dirt,
but in a dirt-bottom pond, they'll root and spread.
--
derek