Explore Plants

Share

Ask Mr. Smarty Plants

Ask Mr. Smarty Plants is a free service provided by the staff and volunteers at the Lady Bird Johnson Wildflower Center.

Search Smarty Plants
    
 

Can't find the answer in our existing FAQs, submit a question to Mr. Smarty Plants.
Need help with plant identification, visit the plant identification page.

rate this answer
Not Yet Rated

Thursday - September 06, 2007

From: Maple Valley, WA
Region: Northwest
Topic: Erosion Control
Title: Erosion control plantings in Washington state
Answered by: Nan Hampton

QUESTION:

Hi, I am trying to do an eagle project that involves putting vegetation onto a hill to prevent erosion. I live in Washington state where there is plenty of rain so erosion is a big problem. We are trying to work with dirt that rarely gets watered except by rain, and is extremely rocky. What kinds of plants would hold together a hillside and could be planted in abundance for cheap?

ANSWER:

The best plants for controlling erosion are grasses because of their extensive fibrous root systems. Below are grasses native to King County Washington that should work well for your project.

Agrostis exarata (spike bentgrass)

Bromus carinatus (California brome)

Danthonia californica (California oatgrass)

Deschampsia caespitosa (tufted hairgrass)

Dichanthelium acuminatum var. fasciculatum (western panicgrass)

Elymus glaucus (blue wildrye) — especially recommended for erosion control

Festuca occidentalis (western fescue)

Koeleria macrantha (prairie Junegrass)

The cheapest way to carry out your project is by sowing grass seeds. However, since you would be sowing the seeds on a hillside, rain is likely to wash the seeds away before they have had a chance to germinate. You might be able to find grass plugs available for sale. They will be more expensive than the seeds but would have a better chance of setting their roots before rain could wash them away. Another (alas, more expensive) possibility is to use erosion control blankets to stabilize the erosion area. 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 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. You can read about a stream bank stabilization project implemented by the Department of Environmental Services, Arlington, Viriginia.

You can check our National Suppliers Directory for possible sources in your area for grasses and grass seeds.

 

 

More Erosion Control Questions

Limiting erosion around pond from Brooklyn Park MN
May 20, 2013 - Minnesota resident, wants to find plant limit erosion from pond?
view the full question and answer

Full Sun, Wind-Tolerant Shrubs and Vines for Steep MN Hillside
June 26, 2013 - My neighbor and I share a very steep, large (in total almost 200 ft. wide) west-facing hillside in Excelsior, MN on Lake Minnetonka. We both have a flat grass area at the bottom so the hillside does n...
view the full question and answer

Plants for slope on Orcas Island, WA
July 21, 2011 - Hi! What a great site! Okay, I have a home on Orcas Island, WA. We live here from about June through September, but only visit once a month or so the other times of the year. We are looking for somet...
view the full question and answer

Erosion control for steep creek bank in Tennessee
June 12, 2010 - I have creek bank erosion problems in Woodlawn, Tennessee, northwest of Nashville. What plants can I place there. The bank is approximately 12ft almost vertical.
view the full question and answer

Erosion controlling Groundcover for Phenix AL
March 30, 2014 - Hi I am trying to find a grass or ground cover to control erosion on firing range berms which are 1:1 grade on a firing range outside of Phenix City AL. Sandy clay soil, direct sunlight almost all day...
view the full question and answer

Smarty Plants's Facebook profile Support the Wildflower Center by Donating Online or Becoming a Member today.

Mr. Smarty Plants wants you to be his Facebook friend. Click the Facebook icon to add yourself to Mr. Smarty Plants list of friends.