They also provide a spawning area for fish, a hiding place for fry and food for goldfish. Use the same potting mix as for other surfacing plants. Floating plants provide shade and harbor for fish in outdoor ponds. They feed through their roots which are suspended in the water. By shading the water and using the nutrients in it they help in suppressing algae.
Fish use the root masses of some types as spawning mats.
Marginal Plants Pond plants that stand in shallow water with the pot just covered and lift their stems and flowers above it are referred to as marginals. They are best confined to individual pots. Use the same potting mix as for other surfacing plants. Best in a sunny position. Best in a sunny position.