A method for managing plant biomass in a wetland containing floating macrophytes includes the steps of draining a body of water having wetland plants growing thereon and permitting the plants to dry. The dried plant matter is then tilled into the bed of the water body, along with a coagulant. The body of water is then re-flooded, and another remediation cycle begun. In a particular embodiment the bed of the body of water has a first depth over a first area of the bed and a second depth greater than the first depth over a second area of the bed. Drainage is to a depth sufficient to expose the first area and leave depressions above the second area at least partially filled, plants in the depressions serving to re-inoculate the wetland upon reflooding.