Landscaping a Mound

Your soils are clay, your yard is soggy and your home is in the country, chances you have a mound type of septic field. As a mound septic system owner, one of the first questions you may have is, “What am I going to do with this large hill in my yard?”. It is true that the mound, at three or four feet high and up to 90 feet long, offers unique landscaping challenges. Luckily there are things you can do to both protect the mound and make it visually appealing.

This simple seeding of cool-season grasses on a mound is easy to manage and attractive.

Choosing the right plant covering is important to keep soil in place and make your yard attractive. But the wrong plant materials can cause irreparable damage to the mound and compromise the entire septic system. For example, roots from trees and shrubs can interfere with the septic field tiles causing blockage and premature failure. Deep-rooted plant should not be planted within 10 feet of the drainfield. It is also not recommended to plant vegetables or herbs on or near a septic system.
The best types of plants for a mound are low-maintenance grasses or perennial flowers. Be aware that the mound will tend to be dry on the top. Grasses and other ground cover that are drought resistant would be best for this area. Cool-season grasses and native wildflowers, such as prairie clover, purple coneflower, wild geranium, or wild bergamot, may be planted on the sides of the mound. Using native wildflowers not only makes it attractive, but also creates habitat for many pollinator species.
When planting on the mound, use minimal tillage and establish cover as quickly as possible to limit erosion. Traffic should also be kept to minimum to prevent compaction and protect the integrity of the septic field. Be sure to wear gloves when landscaping around a septic system. A definite benefit of landscaping a mound is that you will not need to irrigate it!
While having a mound septic system may not be desirable, the right landscaping can create an attractive and unique feature in your yard. An aesthetically pleasing mound can also serve as a reminder that you are responsible for the maintaining your septic system. Pumping your septic tank every 3-5 years, avoiding septic additives, reducing water use, and protecting your drainfield are the most important things you can to ensure your septic system lasts as long as possible.


This information is part of the Upper Maple River Watershed Restoration Project funded through Michigan Department of environmental Quality’s Nonpoint Source Program by the United States