Planting Over and Around Septic Fields

We get occasional calls from our customers who are redoing landscapes after a new septic system has been installed. “What can I plant on top of my septic field?” they ask, or, “Is it safe to plant shrubs next to a septic system?” Here are some general guidelines.

1. In general, the only plants you should be growing right on top of your septic field are turf grasses or shallow-rooted perennials such as thyme (Thymus vulgaris), stonecrop sedums (Sedum adolphii and others) or creeping phlox (Phlox subulata) in full sun, and wintergreen (Gaultheria procumbens), coral bells (Heuchera) or bishop’s hat (Epimedium x versicolor ‘Sulphureum’) in shade.

Another option for over septics is our “bee lawn” seed mix which includes low-growing grass and wildflowers.

2. Do not plant vegetables over a septic field. Do not construct raised beds on top of septic fields, or lay down landscape fabric. Both of these interfere with soil drying.

3. Do not plant water-loving plants over or near a septic field. These include things like willows, winterberry holly, birch, magnolia, and red-twig dogwoods.

4. Do not plant ground cover such as ivy on top of septic systems. These form thick mats that collect leaves and create a moist environment that doesn’t allow for good water evaporation.

5. If you need to plant shrubs within ten feet of a septic field, use Rhododendrons since they have shallow root systems.