Aquatic plants are not desirable in ponds for a variety of reasons, which include reduced fish production by removal of nutrients, interference with population balance, breeding habitat for mosquitoes, and interference with angling. Aquatic plants can be classified into five basic categories: algae, floating, submergent, emergent, and marginal. Control measures differ for each group, and proper identification of the plant is necessary before the correct control measure can be selected.
Most aquatic plant problems can be prevented in a properly constructed pond by a good fertilization program. Plants need sunlight in order to thrive. If the water depth is a minimum of 2 feet and a satisfactory plankton bloom is maintained by fertilization, sunlight cannot penetrate to the bottom and rooted plants will not grow. For fertilization to be effective, a bloom must be established early before nuisance plants begin to grow. Attempting to fertilize after the plants have become established will only worsen the problem.