The growing season is between April and October depending on what part of the country your in. Lilies should be planted between 12-24 inches below the surface of the water, however, at first they should be introduced into the pond gradually, stand the pot on one or more bricks, so that the crown is a couple of inches below the surface of the water. Remove the bricks as growth increases, until the plant reaches it's permanent base in deep water. The tuber's Are very fragile and the growing tip can break very easily, and in most cases this is the main cause for failure with lotus. The second thing to remember is not to plant the tuber to deep.
Lotus require good rich soil as the lilies do.
Same rule applies to them, no peat moss, or humus, or wood chips, and the lotus require plenty of room to grow. You can use the aquatic lotus pots, again no holes, or you can use a large plastic tub. We use many different sizes, to start with you can use at least a 4-5 gallon pot or tub. Soak the soil and gently lay the tuber horizontally onto the soil, being very careful ,and be sure not to put it to deep into the soil. After you plant it you should still be able to see the whole tuber.