Rent Shop Volunteer Join

Q. Who is Mr. Smarty Plants?

A: There are those who suspect Wildflower Center volunteers are the culpable and capable culprits. Yet, others think staff members play some, albeit small, role. You can torture us with your plant questions, but we will never reveal the Green Guru's secret identity.

Help us grow by giving to the Plant Database Fund or by becoming a member

Did you know you can access the Native Plant Information Network with your web-enabled smartphone?

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
See a list of all Smarty Plants questions

Please forgive us, but Mr. Smarty Plants has been overwhelmed by a flood of mail and must take a break for awhile to catch up. We hope to be accepting new questions again soon. Thank you!

Need help with plant identification, visit the plant identification page.

 
rate this answer
Not Yet Rated

Thursday - July 01, 2010

From: Tupelo, MS
Region: Southeast
Topic: Rain Gardens, Erosion Control, Grasses or Grass-like
Title: Grasses for moist, steep hillside in Tupelo MS
Answered by: Barbara Medford

QUESTION:

I have a very steep bank that I have pampas grass planted in spots. It must be a natural spring in the bank because it stays very wet and runs into the street below. Can you suggest something to plant that will help with the water runoff and still look good? I was thinking of Louisiana swamp iris. Will this work?

ANSWER:

If we may be permitted an editorial comment before we answer your question, Pampas Grass, in our opinion, is a bad choice for landscaping anywhere. It is native to Argentina, and could become the monster that ate Tupelo. See this article Campaign Launched Against Pampas Grass to hear the points against it.

On to the Louisiana Swamp Iris; we had no plant by that common name in our Native Plant Database, but believe it might be Iris fulva (copper iris), which is, indeed, a wetland flower native to both Louisiana and Mississisppi. If there is a low area at the base of the hill and NOT in the street, we would suggest a small rain garden. 

Simply put, a rain garden is a depression in the garden that slows down the flow of water, allowing it to infiltrate the soil instead of allowing it to rush downhill carrying topsoil and pollutants with it.  The depression is planted with plants that are adapted to conditions alternating between very wet and very dry. You will find a very comprehensive publication about rain gardens, along with instructions and plant lists published by the Clean Water Campaign in Atlanta by following this link. Clean Water Atlanta also has a publication and a suggested plant list.

There are several plants, including the copper iris, that can withstand the sometimes wet, sometimes dry area at the bottom of a drainage area. If the water goes straight from the hillside into the street, we don't think an iris would be very successful, because its roots are rhizomes that sit high in the ground and can be washed away. What you need are fibrous-rooted native grasses (NOT pampas grass) that will hold the soil and help prevent erosion, as well as use the moisture to support themselves. Strictly speaking your Rain Garden would not be to clean stormwater pollutants, but to hold spring water in your soil. We are going to our Native Plant Database and find grasses native to the Lee County area, USDA Hardiness Zone 8a. Follow each plant link to our page on that plant for information on projected size, propagation, light requirements and so forth. Because you are dealing with a slope, you will probably want to put in plugs of the grasses you choose, because seed would likely wash away with the first good rain. 

Grasses for Tupelo MS:

Bothriochloa laguroides ssp. torreyana (silver beardgrass)

Carex blanda (eastern woodland sedge)

Chasmanthium latifolium (Inland sea oats)

Elymus virginicus (Virginia wildrye)

Schizachyrium scoparium (little bluestem)

Sorghastrum nutans (Indiangrass)

Tridens flavus (purpletop tridens)

From our Native Plant Image Gallery:


Iris fulva

Bothriochloa laguroides ssp. torreyana

Carex blanda

Chasmanthium latifolium

Elymus virginicus

Schizachyrium scoparium

Sorghastrum nutans

Tridens flavus

 

 

 

 

 

 

 

More Grasses or Grass-like Questions

Native landscaping in Austin
August 24, 2009 - I am planning to convert a pretty large portion (app. 500 sq feet) of my front yard from St. Augustine to an area with native and well-adapted plants. I have solarized the area to kill off grass and ...
view the full question and answer

Sheet mulching before planting Habiturf from Grand Prairie, TX
March 03, 2014 - Have you tried sheet mulching as a bed prep and to kill bermuda grass before planting habituff?
view the full question and answer

Low height, drought tolerant grass for Central Texas
January 22, 2010 - What is the best drought tolerant grass for Central Texas that can be used as a low height lawn? I remember seeing a news account (Austin TV) about some UT research at the Wildflower Center that deve...
view the full question and answer

Privacy screen from Simpsonville SC
May 04, 2013 - My neighbor cut down his part of our shared woods so now we see his whole "outside patio area". What kinds of fast growing shade loving trees and shrubs can we plant on our property line that will c...
view the full question and answer

Invasive Indian paintbrushes in Grawn MI
June 04, 2012 - I have lots of Indian paintbrushes crowding my lawn and taking over the grass..what kills it without killing the grass?
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.