Pond plants that provide the perfect aquatic environment for a koi pond include bog plants, floating plants, submerged aquatic plants and water lilies. Pond plants create oxygen for the fish, provide shade and even serve as a source of food. Because koi fish love eating plant roots, it's a good idea to construct a barrier out of rocks to protect the plants from damage.
Bog plants include species such as the elegant water poppy. It has dark green leaves and yellow flowers. Bluebell is a marsh plant with bluish flowers resembling petunias. The dwarf cattail flourishes easily and has long green grass stems with dark brown spiky blooms. Floating plants grow close to the water's surface. Plants in this category include the lush blue-green parrot's flower, the creeping water hyacinth and water lettuce, which resembles a head of lettuce.
Submerged water plants remain underwater and include the anacharis, which has a bright green color. This plant is also known as Brazilian waterweed. The cabomba has two-toned green and purple foliage. Water lilies are among the most popular aquatic plants. Some notable water lily plants are Perry's baby red, with bright red blooms; colorata, with blue flowers and Perry's double white, with large white blooms.