Host an Event Volunteer Join Tickets

Support the plant database you love!

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

Tuesday - March 31, 2009

From: Edom, TX
Region: Southwest
Topic: Erosion Control
Title: Erosion under a Live Oak in Edom TX
Answered by: Barbara Medford

QUESTION:

We have a large Live Oak tree in the front yard that I wouldn't part with for the world. The soil is almost solid sand underneath the tree, and in deep shade. It is on a slight slope and eroding with each rain. Is there anything that would stop the erosion and satisfy the family's need for a lawn to play on? We have tried St. Augustine, but there has been too much drought to keep it watered.

ANSWER:

You have several issues in this situation. The sand, pretty normal for East Texas, is more prone to erosion than some of the firmer limestone or clay soils. The deep shade under the live oak is going to discourage many ground covers. Oak trees have a tendency to allelopathy; that is, they emit chemical substances to inhibit the growth of competing plants beneath them. We're sorry your St. Augustine failed, but not real sorry, because it is a non-native grass that slurps water. Although it is a shade-tolerant grass, the various problems cited above were probably too much for it.

The best plants for preventing erosion are native grasses, with their fibrous roots that grab and hold the soil. Again, the shade of the tree is is not going to permit a number of grasses to flourish. There are some grasses that will tolerate shade, which we consider less than 2 hours of sun a day, but they are not turf grasses, and will not give you a lawn to play on. 

Let's consider a multi-task approach to this situation, beginning with the deepest shade under the tree. Your best bet there is a good quality shredded hardwood mulch that will protect the tree roots, and replace some of the soil lost to erosion. In fact, as the mulch decomposes, it will change the structure of the sandy soil to some extent, and over time should help with the erosion.  The mulch will also permit foot traffic and activity; some playgrounds use mulch in their traffic areas. Ranging out from there into the dappled shade near the edge of the canopy, we can recommend some grasses good in shade and some low ground covers. Again, these will not withstand a lot of foot traffic, but they won't need to be mowed, and perhaps mulch pathways can be laid down between the grasses. 

Shade Tolerant Native Grasses

Andropogon gerardii (big bluestem)

Andropogon virginicus (broomsedge bluestem)

Bouteloua curtipendula (sideoats grama)

Chasmanthium latifolium (Inland sea oats)

Panicum virgatum (switchgrass)

Schizachyrium scoparium (little bluestem)

Sorghastrum nutans (Indiangrass)

Tripsacum dactyloides (eastern gamagrass)

Groundcovers

Phlox divaricata (wild blue phlox)

Phlox pilosa (downy phlox)

Phyla nodiflora (turkey tangle fogfruit)

Dichondra carolinensis (Carolina ponysfoot)


Andropogon gerardii

Andropogon virginicus

Bouteloua curtipendula

Chasmanthium latifolium

Panicum virgatum

Schizachyrium scoparium

Sorghastrum nutans

Tripsacum dactyloides

Phlox divaricata

Phlox pilosa

Phyla nodiflora

Dichondra carolinensis

 

 

 

 

More Erosion Control Questions

Dealing with rain runoff on a slope in Austin
March 24, 2012 - Our lawn is a year old and slopes at about a 45 degree angle with a lot of small holes and tiny gullies from water run-off. I have tried packing them with soil, but it washes away in the rain. Would ...
view the full question and answer

Stream Bank Erosion Control for Bryan/College Station
August 16, 2012 - I live in the Bryan/College Station area and need a ground cover to abate erosion on the bank of an intermittent stream. The bank is shaded. Do you have any suggestions?
view the full question and answer

Plants for erosion control in IL
April 21, 2011 - Steep 40ft slope in rural Illinois with Sandy soil. Recently several trees slid down this slope due to wet conditions. We need any inexpensive plants to hold the hillside in check before erosion creep...
view the full question and answer

Landscaping recommendations for site in Dubuque, IA
March 27, 2010 - I need a seed recommendation. Here are the variables: Location: Dubuque, IA (east Central Iowa) Soil type: Sandy to sandy and gravelly. Part is a riverbank facing east. Steep bank then flat to ...
view the full question and answer

Use of native grasses as erosion control in Austin, TX
June 20, 2006 - We're in Austin, TX and trying to keep our neighborhood lot as natural as possible; however, our lot is eroding and depositing mud and dirt onto the sidewalk whenever it rains. We're looking for an ...
view the full question and answer

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