A benthic screen for controlling aquatic plant growth comprising a sheet of flexible material, a plurality of spaced-apart, elongated retaining members that are transversely positioned across the width of the sheet and attachment means for securing each retaining member to the sheet. The sheet of flexible material is typically a polymeric material having low light transmittance such as a woven geotextile polypropylene. The retaining members are preferably a plurality of parallel positioned metal rods. The attachment means is preferably a plurality of PVC pipes wherein each pipe has a slit that passes through the pipe and extends the length thereof. A portion of the sheet is inserted into a slit and looped around a retaining rod that is encased in the pipe. The structure of the screen renders it self anchoring and provides channels for removing plant decomposition gases that would otherwise accumulate under the screen.