Can I plant trees over my septic system?

No, not over the drainfield or tank. Roots follow water and nutrients, and they grow into pipes, tanks and trenches, clogging and breaking them. EPA says tree and shrub roots “can ensnarl and damage drainfield pipes,” and University of Missouri Extension advises avoiding “water-loving trees and shrubs whose deep roots can damage piping,” adding that “grass is the best drainfield cover.”¹ Keep trees well away from the drainfield, reserve area, tank and the pipes between them. How far depends on the species, since willows, poplars, maples and other thirsty trees reach much farther than small ornamentals; a local nursery, extension office or the county can suggest a distance, and some counties publish one. If there are already trees near an existing system, have a septic professional check for root intrusion during the next inspection.

Citations

1. U.S. EPA, How to Care for Your Septic System; University of Missouri Extension, Household Wastewater: Septic Systems (EQM104F); University of Florida IFAS Extension, Landscaping on or near Septic Drain Fields. ↩