Add a splash of color to your backyard garden feature or pond with water lilies. Water lilies can be purchased at most garden stores and nurseries. After bringing them home, dig the lilies into a pot to provide their roots with the nutrients they need to thrive in your pond. Specific precautions must be taken to ensure the health of the plants and to prevent the potting material from simply floating away and destroying the beauty of your pond.
Select a pot to accommodate the water lily's specialized needs. Because the plant's roots grow horizontally rather than vertically, choose a wide and shallow pot that has no drainage holes and measures 15 to 18 inches across and 8 to 10 inches deep.
Fill the pot to 1 to 2 inches below its brim with standard topsoil. Mix in standard aquatic fertilizer tablets or pellets to provide your water lily with nutrients. Apply the fertilizer according to its label's guidelines, as nutritional potency varies by product.
Plant the water lily so that the plant's tubers are approximately 1/2 inch below the surface of the soil. Once planted, top off the pot with gravel so it's filled to its brim. This helps keep the soil in the pot.
Submerge the pot into your water feature or garden pond. Place the pot in an area where the top of the pot is approximately a foot below the surface of the water, or deep enough that the lily's leaves are floating on the water's surface.