10 Landscaping Ideas for Over a Septic Tank

Landscaping your yard can feel like the ultimate beautification of your home. Not only is it going to define how others see your house as they drive past, but it will hopefully be yours to enjoy for many years. However, while landscaping you need to take care to not damage any of the structures of your house.

Most people know you don’t plant trees next to your foundation, but did you know you also need to pay special attention to your septic tank’s location? Your septic tank is only about a foot underground, meaning that poorly planned flowerbeds can destroy your system. This is an expensive fix, and an ounce of prevention is worth a pound of cure.

Any plant with a shallow root system is a good choice for on top of your septic tank, we’ll go over several options together below!

Can You Landscape Over and Around a Septic Tank?

Yes, you can landscape over and around your septic tank. While you need to be a little careful, landscaping over and around your septic tank isn’t inherently problematic. Make sure you do not place anything with deep roots or that is buried more than five inches down. Additionally, keep in mind that it will need to be removed for maintenance every five years or so, but landscape to your hearts’ content.

Why Can’t Your Grow Trees Around Your Septic Tank?

Trees and some shrubs have root systems that go deep down into the soil. This makes them great low maintenance options, since they tap directly into the water table and rarely require watering, but it also makes them a terrible choice around a septic tank. Septic tanks are shallowly buried structures made of fiberglass or concrete.

Roots, especially tree roots, are strong and can squeeze and crack the tank as the tree grows. Just like you need to keep trees away from your foundation, it is of the utmost importance to keep them away from your septic tank.

What Types of Plants are Safe Around Your Septic Tank?

So, if you can’t use trees to beautify the area around the septic tank, what can you use? Well, the answer is anything with a shallow root system. This includes many perennial flowers, ornamental grasses, shrubs, and groundcovers. There are almost certainly native plants that fit this criterion if you’d like to focus on those, but here are ten popular ideas for septic tank friendly landscaping:

10 Landscaping Ideas for Over a Septic Tank

1. Hydrangeas


Hydrangeas are a garden staple. They can be used as edging, a low hedge, or simply as a flower. They have large round blooms in many colors, as well as shallow roots. They flower from early spring into autumn, and their root systems only go about six inches deep.

2. Japanese Forest Grass

Japanese Forest Grass

Japanese Forest Grass is an ornamental grass that thrives in the shade. It forms mounds of leaves about 12 inches in diameter, with roots that extend a maximum of seven inches. Japanese forest grass is a slow growing perennial, meaning it will come back year after year in your garden.

3. Hostas


Hostas are white, lavender, or pink flowering plants that prefer partial sun. The foliage is very wide and clumping, while the flower stalks are tall. Their root systems are only about four inches deep, though they tend to be wide. Hostas are one of the most common perennial plants because they are easy to care for and hardy.

4. Pink Muhly Grass

Pink Muhly Grass

Pink Muhly Grass is an ornamental grass with a pink feathery appearance. Native to the Southwestern United States, it does best in moderately wet, sunny conditions. Like most grasses, its’ roots are only six inches deep, and it flowers comes back each year and spread at a moderate pace.

5. Boxwood Shrubs

Boxwood Shrubs

Boxwood Shrubs are a dense, green shrub with a spring bloom time. The roots are very shallow, only about three inches deep, so using a garden mulch to protect them from the heat of the sun may be necessary. When used as a hedge, routine maintenance need only be a biannual pruning.

6. Rhododendrons


Rhododendrons are gorgeous, showy flowering shrubs. They come in a wide variety of colors, even greater than roses. They require a loamy soil, and their roots extend between five and eight inches deep. Despite all these attractive factors, you should handle these plants with care, as they are toxic.

Animals who eat the leaves, or people who are exposed to too much of the nectar (usually through handling or honey made with the nectar) become quite sick. If you choose to cultivate Rhododendrons, make sure to use gloves when tending to them.

7. Blue Fescue

Blue Fescue

Blue Fescue is a small ornamental perennial grass with a blue hue. It tolerates a variety of climates and is very tidy in appearance. Perfect for not only low maintenance gardens, but its shallow root system also makes it ideal for landscaping around septic tanks.

The roots typically only reach four inches underground. The dead leaves remain attached loosely to the plant, but you can generally remove them easily by combing through the plant with your fingers.

8. Liriope


Liriope may look like a grass, but it is a purple flowering perennial. Related to asparagus, Liriopes can be planted in full to partial sun. They have a narrow blooming window of August to September, but their foliage is also a gorgeous vibrant green. Mature plants can be up to two feet tall and are hardy.

Despite their size, the root system goes about seven inches deep and should be adequately shallow for landscaping around a septic tank.

9. Periwinkle


Periwinkle is ideal as a ground cover, with a growth height of only a couple inches and a sprawling, spreading pattern. It is very weed resistant because of its dense growth pattern and will come back each year. Its’ flowers are purple and bloom from mid spring to late summer.

The roots are also very shallow at only three to four inches deep. It tolerates shade well and is a good partner plant for one of the taller species on this list.

10. Fountain Grass

Fountain Grass

Fountain Grass is a group of plants known for their fuzzy flowering stems. They come is a variety of shades and are perennial. Like most grasses, their roots extend about four inches deep, and are very dense. You can expect a mature plant to be between one and four feet tall, depending on soil quality and variety.

What Plants Should You Avoid Planting Over a Septic Tank?

There are many types of plants you will want to steer clear of when landscaping around your septic tank. Any deep-rooted plants will damage the tank or pipes, which is something best avoided. Most trees and many shrubs will fall into this category, but some flowers and groundcovers are also deep rooted. Common yard plants you do not want around your septic tank include:

  • Birch Trees
  • Maple Trees
  • Bugleweed
  • Japanese Willow Shrubs
  • Aspen Trees
  • Pine Trees
  • Cactuses
  • Wintercreeper
  • Vetiver Grass
  • Serviceberry
  • Cascara
  • Hooker Willow

What Happens if a Root Damages Your Septic Tank or Lines?

If a root damages your septic tank or its’ lines, you should call a contractor immediately. An improperly working septic tank poses a health risk to you and your family. The most common type of damage caused by plants is cracking of the pipes or tank.

This will cause sewage to escape into the yard. Depending on the amount of damage, the leak may be small, but do not let this delay you, since sewage is a breeding ground for dangerous diseases.

How Much Does It Cost to Repair a Septic Tank?

Repairing a septic tank can be rather pricey. Depending on the extent of the repairs, and how difficult it is to access the tank, you may be looking at several thousand dollars. Despite this high price tag, getting it fixed as soon as possible is paramount. This is what emergency funds and credit cards are made for. Until the damage is repaired, you will likely be without working plumbing in your home, so consider added cost of a hotel.

Final Thoughts

When landscaping around your septic tank and septic lines, using the right plants is important. Plants with deep roots can cause damage, usually in the form of cracking, to the system which is an expensive and smelly affair. However, this doesn’t mean you can’t landscape around your tank. You simply need to use shallow rooted plants. This includes many perennial flowers, groundcovers, and grasses.

Most plant supply stores will be able to advise you on the root system of a particular plant, but we’ve also included some popular shallow rooted plants, and some ones to avoid just in case. Happy planting!

Read our related landscaping post “Landscaping Along the House: 25 Inspiring Ideas” here. 

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