Native Plants

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Sunday - July 25, 2010

From: Goldsboro, NC
Region: Southeast
Topic: Compost and Mulch, Erosion Control, Grasses or Grass-like, Shrubs
Title: Holding soil on a bank in Goldsboro, NC
Answered by: Barbara Medford

QUESTION:

I live in Goldsboro, NC on a small ridge with a very steep bank on one side of our property. What native plants can we plant on the bank to help hold the soil. Also, what would be best to plant on the ridge? We recently had to remove a couple of trees (too close to our house)from the ridge, but have left the trunks to rot hoping to hold the soil until we can establish new plants or low growing or small trees. Thank you

ANSWER:

Since we don't know what is the amount of sunlight on either spot, the slope or the ridge, nor whether you will have irrigation or even how much space you have, we can't give you an exact landscape recommendation. However, we can make some suggestions and then refer you to our Native Plant Database, where you can make some of your own choices. As is our practice at the Lady Bird Johnson Wildflower Center, everything we recommend will be native not only to North Carolina, but to the area in and around Wayne County, west central North Carolina, USDA Hardiness Zone 7b.

We recommend grasses for controlling erosion because of their extensive fibrous root systems that serve to hold the soil in place. However, seeding grass is not the whole process. The seeds need moisture to germinate. If the moisture comes in the form of rain, it is likely to wash the seeds down the bank before they have a chance to germinate and take root. There are two possible solutions—an erosion control blanket or pneumatic compost/seed application. The erosion-control fabric works by slowing the runoff water and allowing sediments 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. You can also insert plants into the soil by cutting through the matting. The roots of the plants that are growing through the erosion-control material anchor the soil to stop the erosion. If you use erosion-control blankets made of biodegrable material, they will eventually disappear leaving the plants to control the problem. Many nurseries carry this erosion control fabric.

The compost/seed application may be a bit more complicated and expensive than you had in mind since it does require a pneumatic blower, or some mechanical means, to spread the compost/seed mix. The US Composting Council offers information about suppliers of compost and compost technology, but we don't really know if this could be a do-it-yourself project. You might check with a landscaping or environmental consulting company in your area who might have the machinery to do this to learn about the feasibility and expense of applying the compost/seed mixture this way. You can find the names of Landscape Professionals and Environmental Consultants in your area that specialize in native plants by searching in our National Suppliers Directory.

We will go to our Native Plant Database and find grasses and perhaps some spreading shrubs native to North Carolina that should help with your erosion be atttractive on the ridge. These are not lawn-type mowable grasses, but more decorative prairie grasses that, being native to North Carolina, will be able to cope with soil and climatic conditions. Follow each plant link to the page on the individual plant for information on expected size and sun requirements. You can repeat this process, doing your own search, by going to our Native Plant Database, selecting on North Carolina, and then indicating the amount of sun available, soil moisture, etc.

Grasses for Erosion in Wayne County, North Carolina:

Andropogon gerardii (big bluestem)

Chasmanthium latifolium (Inland sea oats)

Muhlenbergia capillaris (hairawn muhly)

Muhlenbergia schreberi (nimblewill)

Paspalum floridanum (Florida paspalum)

Schizachyrium scoparium (little bluestem)

Sorghastrum nutans (Indiangrass)

Tridens flavus (purpletop tridens)

Shrubs for Wayne County, North Carolina:

Cephalanthus occidentalis (common buttonbush)

Hydrangea arborescens (wild hydrangea)