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Saturday - November 27, 2010

From: Atlanta, GA
Region: Southeast
Topic: Compost and Mulch, Soils, Erosion Control, Shade Tolerant, Ferns, Grasses or Grass-like, Shrubs
Title: Erosion control on partially shaded slope
Answered by: Guy Thompson


Mr. Smarty Plants, I live in Atlanta, GA. My house is on a hill, and I am beginning to have erosion at my backyard porch (concrete slab, on the corners especially). The soil is mainly red clay, and it washes away rather vigorously during heavy rains, exposing more of the concrete each time. I am looking for an attractive plant/shrub or grass, as it is our sitting area, that I can plant (partial shade) to prevent this. I do have some moss growing and am not sure if that will help with erosion control. Please help as I am afraid that my slab will crack eventually. Thank you David


Mr. Smarty Plants can suggest several plants that will form mats and control erosion. But before planting anything it would be desirable to amend your red clay soil with peat moss and good compost to provide nutrients and water-holding capacity. If you prefer low-growing species, you might consider Pachysandra procumbens (Allegheny spurge) or Mitchella repens (Partridgeberry). These native perennials prefer a rather shady site but should do well in your partial shade if kept fairly moist. They will prosper most if shaded during midday. Another possibility is Phlox subulata (Moss phlox), which can tolerate more sun. These and more suggestions are mentioned at the Georgia Native Plant Society web site.

Ferns can prevent erosion too. A good choice for partial shade would be Polystichum acrostichoides (Christmas fern), which, like the other species mentioned above, is evergreen. Grasses can be effective in erosion control. Uniola paniculata (Sea oats) is a common plant on coastal sand dunes but can be grown inland in full or partial sun, producing a flowering spike about three feet high. If you would prefer a somewhat smaller grass, you might consider Chasmanthium latifolium (Inland sea oats). This very attractive grass forms unusual flat seeds on heads rising to about two feet. It does well in shade or partial shade. Both the recommended grasses are perennials, but the vegetative parts die back in winter.

To view more information on the choices suggested, click on the scientific name of the plant in the text above. Attached below are representative images of the recommended species.


From the Image Gallery

Allegheny spurge
Pachysandra procumbens

Mitchella repens

Creeping phlox
Phlox subulata

Christmas fern
Polystichum acrostichoides

Sea oats
Uniola paniculata

Inland sea oats
Chasmanthium latifolium

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