Ask Mr. Smarty Plants

Grasses are an excellent solution for erosion control because of their extensive fibrous root systems.   Most grasses grow best in full sun; however, there are some that will do well in shade and part shade.  Here are some that are native to Illinois.

Andropogon virginicus (Broomsedge bluestem) is noted for its use for erosion control and grows in partial shade and can grow in very acid soils.

Chasmanthium latifolium (Inland sea oats) is an attractive bunch grass that grows in shade and part shade and in soils with pH 5.0 to 7.0.

Elymus canadensis (Canada wild rye) grows in sun and part shade with a soil pH range of 5.0 to 7.9.

Elymus virginicus (Virginia wildrye) grows in partial shade and grows in soils of pH 5.0  to 7.4.

Panicum virgatum (Switchgrass) grows in sun and part shade with a wide range of soil pH values, from 4.5 to 7.5.

Sorghastrum nutans (Indiangrass) grows in sun, part shade and shade.   It will tolerate a wide range of soil pH values, from 5.0 to 7.8.

All the above grasses can grow from 2 to 5 feet tall (even 8 feet tall—Indiangrass).  You could potentially use a variety of them for an interesting appearance.  Sedges are very grass-like and tend to be shorter and of a more even height.  Many of them are evergreen.  Here is one recommended one:

Carex blanda (Eastern woodland sedge) is an evergreen sedge that grows in sun, part shade and shade and will grow in very acidic soils from pH 4.4 to 7.0.

You could also add low-growing shrubs to the mix.  Here are a few:

Aralia nudicaulis (Wild sarsaparilla) grows in the shade and prefers acid, sandy soil, pH 5 to 6.

Chimaphila maculata (Striped prince's pine) is a low plant with striped, evergreen leaves that grows well in acidic woods.

Chimaphila umbellata (Pipsissewa) also has evergreen leaves (but without the stripes) and grows in acidic soils, pH 5 to 6.

Ferns and other non-flowering plants that grow in the shade are other good choices:

Lycopodium obscurum (Rare clubmoss), an evergreen, non-flowering plant that grows in the shade and tolerates a wide range of pH values.

All the ferns listed below grow in the shade and in acidic soils.

Athyrium filix-femina (Common ladyfern)

Dryopteris carthusiana (Shield fern)

Osmunda cinnamomea (Cinnamon fern)

Polystichum acrostichoides (Christmas fern)

If your slope is very steep and bare, you may want to consider erosion-control blankets to stabilize the erosion area so that seeds have a better chance to germinate and become established. The erosion-control fabric works by slowing the runoff water and allowing sediment to fall out rather than be washed away. Seeds are sown under the erosion-control material and grow up through the matting when they germinate. Underneath the matting the roots of the plants growing through the erosion-control material anchor the soil to stop the erosion. If you use erosion-control blankets made of biodegradable material, they will eventually disappear leaving the plants to control the problem. Seeds can be sown under an erosion control blanket or grass plugs and other plants can be planted by cutting holes through the blanket.  This material is available at most nurseries.  In the linked article above from the University of Washington there are descriptions of other erosion control materials that can be used.  Your slope might also benefit from some of the other methods discussed there.

Below are photos from our Image Gallery of some of the recommended plants.