If you want to put plantings on or near your POWTS you should plant species of plants that have a herbaceous root system. If you select plants that have a woody root system and plant them very close to, or on top of, the absorption field it will experience root problems. The roots from this plant group tend to grow or migrate in the direction of a moisture source and work their way into the piping network. Once inside the network the roots begin to clog the piping. Given sufficient time the roots will cause system failure. The alternative to a woody root plant species could be flowers or wildflower seeding.