How to Landscape Around a Septic Mound System in a Back Yard

A mound septic system in your yard can be challenging to landscape, because the mound is usually 3 or 4 feet tall and up to 90 feet long. Mound septic systems are installed when there isn’t 3 feet of unsaturated soil available between the drain field or “leach field” pipes and the ground surface, thus making it necessary to mound up soil on top of the drain field area. Landscaping around and on top of the mound requires some careful planning. You’ll need to select the correct plants that won’t damage the underground septic system and provide the beneficial moisture and nutrient absorption while providing soil aeration and erosion control.

Wildflower or grass seeds
Shallow-rooted plants or groundcovers
Shrubs and trees (optional)
Topsoil
Organic compost
Garden rake
Small spade or trowel
Garden hose with spray nozzle

Instructions

- 1
  Select native, drought-resistant, shallow-rooted plants, groundcovers and grasses to plant on top of the mound. Don’t plant shrubs, trees or plants that require extra care or water, or grasses that require irrigation or frequent mowing.
- 2
  Choose plants, trees or shrubs for landscaping around the mound. Don’t choose vegetable plants or herbs for planting around or on top of the mound.
- 3
  Spread a thin layer of topsoil on top of and around the mound. Make the topsoil layer 6 to 16 inches deep.
- 4
  Sprinkle a thin layer of organic compost on the topsoil and gently work the compost into the topsoil using a garden rake. Don’t add fertilizers.
- 5
  Spread the wildflower, grass or other shallow-rooted plant seeds onto the topsoil on the mound. You can press the seeds down into the soil gently with your hands or rake them into the top 1 or 2 inches of topsoil.
- 6
  Dig shallow planting holes that are just deep enough to cover the roots when planting container plants, such as groundcovers, on the mound. The planting holes should be no more than 12 inches deep.
- 7
  Water the seeds or plants on the mound lightly to moisten the topsoil after planting them using a spray nozzle on your garden hose. Don’t water these plants after the one initial watering.
- 8
  Dig planting holes that are the same depth as and twice the diameter of the tree or shrub containers or root balls when planting these around the perimeter of the mound. Plant the deeper-rooted shrubs and trees at least 20 feet away from the mound’s perimeter, or at least 50 feet away from the mound if you’re planting maple, willow, elm or poplar trees.

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