A water garden can add a new element to a backyard landscape and expands your options when it comes to choosing plants to grow. Just like their terrestrial counterparts, an aquatic plant needs potting unless it's a strictly surface-floating species. Provide the aquatic vegetation with the potting environment they need to thrive and grow into a lush and colorful water garden.
Select a pot. Any standard plant pot can be used. For most aquatic plants, the University of Illinois Extension suggests using containers that measure 6 to 20 inches in diameter and 10 inches deep. The larger the pot, the bigger your aquatic vegetation can grow.
Fill the pot 2/3 full of clay-based garden loam or a potting soil mix specifically labeled for use in water gardens.
Place the aquatic plant's rhizome or roots in the center of the pot and cover the rhizome or plant roots with 2 inches of soil.
Layer 3/4 inches of gravel on top of the soil. This keeps the soil from becoming waterborne and turning the water cloudy, according to the University of Illinois Extension.
Arrange bricks, upside down pots or similar structures in your water garden. Set the potted aquatic plant pot on the structures so that the plant's foliage is just level with the water surface, according to Colorado State University Extension. Adjust the bricks as needed to bring the pot higher or lower.