Ask Mr. Smarty Plants

First, I’ll direct you to four publications that explain the “what, when, where, and why” of  windbreaks. These cover the reasons for planting windbreaks, their design, and plant selection.

Iowa State University  Extension;

     Publication 1716, 

      Publication 1717.

USDA-NRCS;  WIndbreaks , Their Use

Department of Natural Resources, State of Ohio; Why Plant A Windbreak

For further plant selection, let me introduce you to the Native Plant Database. We can use it to help us select some plants for your situation. One way of using the Database is to go to the Recommended Species Lists. Click on “View Recommended Species Page”, and then click on East Texas on the map. This will bring up 133 commercially available native plant species suitable for planned landscapes in East Texas. This is more information than you need, so go to the Narrow Your Search box to the right of the window and make the following selections: select Texas under State, Shrub under habit, and Perennial under duration. Check the appropriate boxes under Light Requirement and Soil Moisture for your location. Click on the Narrow Your Search button and the list is reduced. Clicking on the scientific name of each plant will bring up its NPIN page that has plant characteristics, growth requirements and photos.  As you check through the list note the light requirements, moisture requirements, preferred soil types of the plants you are considering.

Here are a couple of links that can help you deal with your clay soil.
Bachmans Gardens  

fine Gardening  

This link to the USDA-Forest Service sort of sums up our feelings about Elaeagnus.