Can Knock Out roses be grown near a septic tank? Do you have any other recommendations for small bushes that can be planted near a septic tank?
The Gardener’s Answer
Hello, Terri in Kentucky: From my limited knowledge of landscaping around a septic tank, it is important to carefully place plant material so that it does not interfere with the functionality of the system. If placed properly, plants can be beneficial in terms of absorbing moisture and nutrients as well as preventing erosion. It is generally recommended that trees and shrubs should be planted a minimum of 20 feet away from the septic system. Choosing plant material that does not require a lot of consistent moisture will be the best options in the long run. Wild flowers and grasses are good choices for this environment. Asters, coneflowers, false sunflower (Helianthus), liatrus, penstemon, and monarda are all good options for sun-loving perennials. Switchgrass and Little Bluestem are great choices for a native grasses. As a general rule, the larger the plant the larger the root system. This does not necessarily mean that the roots go any deeper. As for planting a Knock Out rose in the area, you should be fine as long as you are not planting over an absorption field. Other small shrubs to choose from would be spirea, hypericum, and smaller viburnums. The Indiana Extension office has a good publication on plant material that does well around a septic system. To read this publication you can visit www.extension.purdue.edu/extmedia/HENV/HENV-15-W.pdf
. Always wear gloves when planting around a septic system, and avoid planting any edibles in this space.