Depending on where your septic tank is located, landscaping over it can be a challenge. Homeowners want their yards to be attractive, but just camouflaging the tank with beautiful landscaping doesn't always work. There are a few soil conditions that restrict what you can grow, but the bigger problem is the possibility of ruining your plumbing.
If the tank lies under a vast expanse of grass and you want a lush green lawn, this usually isn't a problem. Generally, grass grows extremely well over septic tanks and leach fields because the system provides lots of natural fertilizer. However, if the tank is located in a low spot and the area collects water, you may need to consult with a landscaper or lawn specialist to determine what type of grass is best. You may need a taller grass with stronger roots to help prevent soil erosion, since erosion can make the leach field work less efficiently.
Ground covers like Pachysandra and ferns can be ideal but should be used judiciously. They are popular as landscaping elements because they grow quickly, don't need to be mowed and can fill large areas with low-maintenance greenery. However, if the septic tank is located in a shady area you don't want a ground cover that's too lush or dense. Too much shade cools the ground and interferes with the decomposition process in the leach field. The ground cover should allow for a slightly warm environment and occasional sunlight so the soil can dry out periodically.
Flowers, Shrubs and Woody Plants
If the septic system is located under a cultivated area like a garden, landscaping elements become more important. Annual flowers are usually fine because they have very small, shallow roots and die after one season. However, perennial shrubs and woody plants like rosebushes and lilacs can be dangerous to your septic system. Some shrubs have far-reaching roots that grow each year and can work their way into the pipes and plumbing. Landscapers can sometimes prevent root damage by installing root barriers to direct root growth away from the tank or the plumbing. However, according to the Clemson University Extension, woody plants like shrubs should be planted at least 10 feet away from leach fields and drain lines.
Trees are the most dangerous landscaping element to your home's septic system. Some trees have larger and thirstier roots than others, but they will all follow the water right into your leach field, tank, drain lines and even into your basement. Large roots can clog and break drain lines, and they can be expensive and difficult to get rid of. If you need to incorporate a shade element or sound barrier into your landscaping, consult a professional for septic-safe alternatives to trees. Sometimes you can plant a row of boxwoods or junipers safely, depending how the system is situated.
The ground over the septic system might need landscaping to make it attractive, but it's very easy to ruin your plumbing with the wrong plants. A professional landscaper like Ralph Wells Landscaping can tell you which grasses, ground cover, shrubs and trees are best for your yard and soil conditions to keep your plumbing safe.