What Ground Cover Should Not Be Planted over Septic Systems?
Ivy, Pachysandra, Similar Ground Covers are NOT OK for use over a septic drainfield: these plants will reduce effluent evaporation from the drainfield, soil absorption system, soakaway system, or mound soils. A second reason to keep these plants away from septic system fields is because their roots often invade and clog effluent distribution piping. The photographs above show pachysandra as a dense ground cover (at left) and typical ground cover north of the arctic circle in Norway (at right). Thick dense vegetation of any sort will conserve moisture to itself and will preven soil transpiration. Over a septic system this means that the portion of effluent disposal that is supposed to be occurring due to evaporation will be reduced and the liquid load on surrounding soils increased – you’ve cut the effectivness and shortened the life of the drainfield by such plantings. These plants are OK, however, for planting over the septic tank itself.
