One of the more frequent questions we are asked is "What can I plant over my drain field?". We do suggest planting grass over your drain field, as it helps with evaporation and providing oxygen to your system. However, it's extremely important to know what else can be planted and what should be avoided. Planting certain types of plants and trees near your drain field can cause it to become root bound and fail prematurely, costing you thousands of dollars.
Non-invasive plants, and those without deep roots are good ideas. Grass is always an excellent choice for planting over a drain field. It's important to avoid planting edible plants such as fruits and vegteables in your drain field area. The consistent, heavy amounts of water required to grow fruits and vegetables could easily flood a drain field. It's not a good idea to plant anything you plan to eat in the soils of your drain field, for obvious reasons. If you'd like to plant something more than grass near your drain field, you can always speak with a gardener, landscaping company or visit a nursery for more information on non-invasive plants.
Typically, shrubs and trees can have some pretty intrusive root systems, which will actively seek water and grow into the legs of your drain field. Invasive roots have been known to break pipes and other important septic components, and grow inside or even break septic tanks. It's important to remember that even though you can't see them, some tree roots can spread out the same height of the tree. It's best to avoid planting trees near your drain field. Certain types of trees, such as alder, cedar, maple, poplar, and willow trees are best avoided, as they can cause the most damage to a drain field. Blackberry bushes, English ivy and ferns are also plants to avoid having near your drain field.
In ground sprinkler systems are not recommended. During warm summer months, watering the lawn is understandable, but limit the amount of water as much as possible. Try to water no more than an inch a week. Remember the more water that goes into your system, the more it will impact your drain field. Keep in mind that septic components can have varying depths, with some being as shallow as 6-12 inches. It's not a good idea to do any heavy digging or rototilling in your drain field, or near the tanks. If you're unsure of where your septic components are, check the Record of Construction, sometimes called an as-built, for your system. If you do not have a copy of this, you can check online here.