plants closer to the uv c lamps the dome will be lowered a milfoil infestation and treat the milfoil with uv c rays the method and apparatus for treating aquatic plants and plant fragments with uv c lamps where the light rays damage the plant cells and cause the plant and plant fragments to die this method causes no other environmental damage like herbicides that contaminate the water and cause plants to build up resistance to the herbicide chemicals the method and apparatus for treating aquatic plants floating on the water surface functions by treating the top and or underside of the floating plants with uv c light rays the uv c lamps may be supported in an open housing and frame supported by pontoons so the uv c light rays are at the desired distance for the top of the plants and or the underside roots of the plant all publications and patent applications mentioned in this specification are indicative of the level of skill of those skilled in the art to which this invention pertains all publications and patent applications are herein incorporated by reference to the same extent as if each individual publication or patent application was specifically and individually indicated to.