Excavate a hole with your fingers or a trowel that is big enough to accommodate the root mass of your parrot feather plant in the underwater gravel, rocks or coarse gritty soil at your planting site. It does not need to be buried in soil, but does need to be anchored at the planting site of choice.
Bury the plant root mass low enough below the water line that roots and at least the first inch or two of plant is submerged under the water. Parrot feather readily adapts to varying planting depths.
Slide the plant out of its pot and set the root ball of the parrot feather plant down into the opening you have made. Alternatively, if you want to control and slightly slow the rooting, you can bury it in the nursery pot it comes in.
Push the gravel, stones or gritty coarse soil around the root mass or pot to effectively anchor it in place where you want the plant base to be positioned. Add enough material to create a natural camouflage for the roots or pot.