I plant in 4 to 6 inches of water. Mine does not grow on dry banks but does survive periodic drying once established. It can spread extensively, but I really like it. I second lizard's tail as an excellent plant. It can form stands where it is planted, but I have not had it move. It is a well behaved plant. Arum is also excellent in my opinion, while duck potato can spread quickly. You can't go wrong with blue flag either.