Floating plants such as Lemna spp. (duckweed) or Azolla filiculoides (fairymoss) have small leaves and can be put straight into the pond. If larger plants like Eichhornia crassipes (water hyacinth) have been bagged up for some time they may have lost some buoyancy. In this case place them gently into a shallow, sheltered area of the pond where they will not be blown about until they grow upright again.
It doesn't really matter where floating plants are placed in the pool as due to their nature they will be blown about on the surface by the wind surface disturbance etc.
Floating plants are not such a good addition to a pond that uses a surface skimmer as the skimmer will inevitably be clogged up within hours.
