Planting on our drainage field

Asked March 27, 2019, 5:00 PM EDT

We are new to the county and live on 2 acres. Part of that is our drainage field which is in full sun. What type of plants can we grow on it? We are interested in pollinator friendly plants and do not want to mow that part of the lawn. Will we have to remove sod to start plants like this or are there some that will take over if we get them started?

Washington County Minnesota native plants drain fields

1 Response

Thank you for the question. Plants suitable for growing over a septic drain field should have shallow roots, be drought tolerant, and require minimal to no dividing or cultivating. Plants benefit the drain field by removing nutrients and moisture from the soil, and retarding soil erosion. Native plants and grasses are good choices, but you need to be aware that some native plants have very long root systems that might interfere with proper drain field function over time.

Here is an excellent publication from University of Michigan Extension that lists many different plants. Most are native and excellent for pollinators and have the correct root structure for your situation: https://www.canr.msu.edu/news/could-you-please-tell-me-what-native-plants-i-can-plant-on-the-drain-field

Yes, you will have to prepare the planting area, just like you would for any garden area, taking care to disturb the soil as little as possible. If you don't, the plants won't get a good start and the sod will overtake the area again. Native plants especially, take a year or two to establish. If they don't have to compete with weeds and sod, all the better. A good way to remember native plant growth rates: "The first year, they sleep, the second year they creep, and the third year they LEAP"! The more care the plants get in their first year, the greater the reward in later years.

Thank you for contacting Extension.