If you’re looking to cultivate water lilies in either a container water garden or a larger pond, the planting process is identical. Begin by selecting a small container, measuring 12-20 inches in diameter and 8-10 inches deep, that will eventually be placed in your pond or tub. Cover the drainage hole with burlap or mesh to prevent the soil from escaping. Because the plant will grow to the size of the container, choose a smaller pot if you are working with a smaller tub instead of a pond.
Fill the pot two-thirds of the way with garden soil or aquatic gardening soil, avoiding lightweight potting mixes containing perlite, vermiculite, or peat. The soil should be heavy to provide the proper environment for the plant. Place the rhizome against the pot’s side, with the growing tip pointing upward at a 45-degree angle toward the center. Cover all but the tip with soil and add a layer of small rocks or pea gravel to stabilize the soil.
When lowering the planted pot into the pond or tub, set it at an angle to let air escape. Position the pot’s base 12-16 inches deep. As the plant grows, its leaves will float to the surface. If your plant already has developing leaves, start by placing the container so that the leaves are 6-8 inches deep. Within a few days, the leaves should reach the surface, and you can then lower the plant to its final depth of 12-16 inches.