These are the slides used by Wild Ones Oak Openings board members in our March 11, 2025 Zoom program. The purpose of the program was to answer questions about native gardening from our members. Additional questions will be answered in upcoming issues of our chapter newsletter.
Is there a list of septic-safe Oak Openings native plants? (Answered by Jon Zabowski)
This is a great question, while I didn’t find a specific list of Oak openings natives, I compiled one by researching a couple of different native seed websites. You will want non-woody, herbaceous plants that are suitable for medium to dry soil, and part shade to full sun. You want plants that like dry soil for a few reasons: Leach fields and septic tanks have stone and gravel that can transport moisture away from the plants, septic tanks can produce heat that affects the soil temperature, and you want plants that don’t readily seek water. Plants that don’t like their roots wet, won’t seek out the moisture in the pipes from the leach field. The plants will absorb moisture from the leach field but not clog up the pipes with their roots.
The depth of the soil over your septic tank and leach field is important to know before starting your project. You could be limited by what types of soil preparation you can use. If the existing cover is turfgrass, you may need to kill the grass before planting. This can be done by tilling, smothering it with a tarp or cardboard, using herbicide to kill the grass, or controlled burning. If the grass is not real dense, you could plant right in the grass and just stop mowing. Eventually the native plants will outcompete the turfgrass. I have had good luck with this in my yard for planting just about anywhere.
Some great Oak Openings natives to use are: Butterfly Milkweed, Western Sunflower, Partridge Pea, Lanced-leaved Coreopsis, Rough Blazingstar, Dotted Horsemint, Hairy Mountain Mint, Wild Bergamot, Wild Lupine, Foxglove Beardtongue, Blue Vervain, Grey-headed Coneflower, Black-eyed Susan, Early Goldenrod, Stiff Goldenrod, Sky Blue Aster, Ohio Spiderwort, Purple Love Grass, Little Bluestem, Indian Grass, Bottlebrush Grass, Pennsylvania Sedge, Fox Sedge, and Canada Wild Rye.
Any combination of these species will be an excellent addition to your yard and the pollinators, and the birds will thank you for it! The grasses and sedges are important host plants for butterflies and skippers too.
Websites Researched:
Ohio Prairie Nursery – septic field native seed mix
Prairie Moon – septic safe seed mix
Wild Ones Oak Openings Region (NW Ohio & SE Michigan) 