The best ground covers for a septic field are shallow-rooted, non-woody plants that thrive without watering or fertilizing. Turf grass (like fine fescue or Kentucky bluegrass) is ideal, while drought-tolerant native meadow mixes or creeping ground covers (like bugleweed, creeping thyme, or moss phlox) offer low-maintenance, colorful alternatives.
Grass is the ideal cover for drainfields. Grasses can be ornamental, mowed in a traditional lawn, or in an unmowed meadow. Or, you can try groundcovers and fems. The key to planting over the drainfield is to select shallow-rooted, low-maintenance, low-water-use plants.
Do: Plant grass or keep existing native vegetation. These are the best covers for your drainfield. Direct all surface drainage away from the septic system.
You can only place lightweight, shallow-rooted vegetation—like turf grass, small wildflowers, or shallow-rooted perennials—on top of a septic field. Avoid structures, heavy traffic, and deep-rooted trees, as they can compact the soil, crush the pipes, or cause expensive blockages.
Creeping Jenny (Lysimachia nummularia), Yellow Archangel (Lamiastrum galeobdolon), and certain mint varieties are among the absolute fastest-spreading ground covers. These plants can easily spread up to 2 feet in a single season.
Thymus serpyllum is the ultimate low-maintenance ground cover. It doesn't require mowing, is loaded with delightful flowers, is nicely drought-tolerant, and is resistant to many pests and diseases. It's even happy in soil conditions where other plants might not thrive.
While creeping phlox is a beautiful, low-maintenance ground cover, its main downsides are a short, 3-to-4 week bloom time, vulnerability to fungal diseases like powdery mildew in damp conditions, and a susceptibility to spider mites in hot, dry weather. It also does not handle heavy foot traffic well.
Can You Put Gravel on Top of a Septic Field? Using gravel on top of a septic field can be decorative, but proceed cautiously. While gravel allows for drainage, excessive amounts can compact the soil, reducing the septic system's efficiency.
The absolute worst thing for a septic tank is introducing harsh chemicals, grease, and non-biodegradable solids, or overwhelming the system with too much water at once. These mistakes kill the beneficial bacteria that break down waste, cause blockages, or permanently destroy the drainage field.
The average lifespan of a septic system is 15 to 40 years, but it can last longer if properly maintained!
Natural bacteria and enzymes already present in a septic system are the primary agents that dissolve poop. To boost this process, use commercial treatments like RID-X (bacteria/enzymes) or DIY solutions like active dry yeast and sugar to help break down sludge and prevent solid buildup.
Here is a general list of plants to avoid near the septic system:
For best results, add 2.5 gallons of BioOne to your pumped septic tank. Then add another 2.5 gallons for every 400 square feet of drain field directly into the header pipe or distribution box. If the drain field has completely failed soil fracturing may also be needed.
Plant shallow-rooted, non-woody plants over your septic field to protect the underground pipes from root intrusion. Ideal choices include turf grasses (like fescue), ornamental grasses, wildflowers, and shallow-rooted perennials like daylilies, irises, and daffodils. Avoid planting trees, large shrubs, and edible vegetables.
What is the recommended trench depth for a drain field? The recommended trench depth for a septic drain field typically ranges from 18 to 30 inches, depending on local regulations and soil conditions. Proper depth ensures effective wastewater treatment and prevents groundwater contamination.
Here are a few additional ground covers to try:
Experts and plumbing professionals generally consider Rid-X to be an unnecessary additive rather than a system-saving necessity. While it won't necessarily damage a properly functioning septic tank, it isn't required for a healthy system, and proper maintenance is far more effective.
Yes, Dawn dish soap is generally considered safe for septic systems. Because its formulas use biodegradable surfactants and are free of phosphates, it won't disrupt the helpful bacteria in your tank when used in reasonable amounts.
Baking soda is sometimes suggested as a natural alternative to commercial septic tank treatments. It's believed to help maintain a balanced pH level in septic systems, which can support the growth of beneficial bacteria that break down waste.
Patios and Other Heavy Landscaping Features
You should also avoid any heavy landscaping structures over leach fields, as the weight of concrete, pavers, and other dense building materials can compact the soil and crush the drain field pipes, leading to serious issues.
Septic drain field rejuvenation is a process used to restore failing or sluggish leach fields without the high cost of total replacement. It typically involves clearing clogged pipes, breaking up the anaerobic biomat (the slimy layer that stops water from draining), and aerating compacted soil.
For a traditional septic drain field, the ideal gravel size is generally between 34three-fourths𝟑𝟒 inch and 2.5 inches in diameter. Local health departments almost universally require the stone to be "washed" or "clean" (free of dirt, sand, and dust fines) so that the void spaces do not get clogged.
Periwinkle is an evergreen, perennial ground cover that forms a dense mat to keep weeds at bay. It tolerates heat, grows about 6 inches high, and produces blue to violet flowers in the spring. It has a rapid growth rate, and its ability to root at the nodes enables periwinkle to form a thick mat over a wide area.
A single creeping phlox (Phlox subulata) plant will typically spread 1 to 2 feet in width, with some varieties reaching up to 3 feet. It grows in a slow, mat-forming habit rather than aggressively taking over.
Kudzu (Pueraria montana) is widely considered the most invasive plant in the US. Nicknamed "the vine that ate the South," it was introduced in 1876 and now covers over 3 million acres across the American Southeast. It grows up to a foot a day, aggressively smothering trees, buildings, and native ecosystems.