Good advice re: the sticky dirt needed and some rocks on top. I just ordered 5 each of Colorado, Lemon Mist, Panama Pacific and Mungkala Ubon from Dusty at Tx. water Lilies. He said in an earthen pond it's best to just plant them directly into the pond or else have to mess with them a lot to get good results; only problem is, the rains have come early and pond is at full pool. It will be down 3-4 ft. by the time the fish really need some shade. I will toy with placing some in semi-floating pallets for a while. He gave me a little discount on 10 ea. Nymphea Odorato just to even out the order; I will start the expensive ones in containers and probably will play with the Odorato's.
