Ask Mr. Smarty Plants

We get a lot of questions every year from people who sound like they are married to their lawns. It's got to be perfect, cover everything right up to the trunks of the trees, green all year, etc. We feel you may be in that category. 

St. Augustine grass, Stenotaphrum secundatum, is native to Africa and therefore out of our range of expertise. Although it is somewhat shade tolerant, it does need some sun to prosper and all grasses find it difficult to do well in the shade of big trees, where their roots are in competition and sometimes the trees (especially oaks) have allelopathic qualities, whereby they emit substances that will discourage grasses or other plants from growing beneath them. Bermudagrass, Cynodon dactylon, is native to Africa and Asia and, especially in the American South, has become one of the most invasive weeds in existence. It requires full sun.

There are some native lawn grasses being developed, but they all need full sun, which we consider to be 6 hours or more of sun a day.  And they need protection from weeds and extra care, at least until they are well-established. You may have to accept that you are not going to have a perfect year-round lawn. Some of the shaded areas may need to be replaced with beds of native shade plants, including some native ornamental grasses. The areas directly under the trees should probably be mulched with a shredded bark mulch. This will shade the tree roots, help keep them cool or warm, depending on the season, and hold in moisture. As the mulch decomposes (and it will have to be periodically renewed) the decomposed material will help the soil, enriching it and improving drainage. 

We are not too familiar with the overseeding process of annual grasses to keep the area green in winter, but it does require a good deal in resources, water, seed and fertilizer, and then summer grasses with which you are already having difficulty are going to have to cope with the winter grasses. You probably have a lovely property, but in these days of diminishing resources, a lower use of those resources is certainly a better environmental choice. Cheaper, too. 

So, on to your neighbor's fescues. There are three members of the Festuca (Fescue) genus native to Texas:

Festuca rubra (red fescue) - intolerant of shade

Festuca subverticillata (nodding fescue) - can tolerate part shade, 2 to 6 hours of sun

Festuca versuta (Texas fescue) 

None of these is shown in the USDA Plant Profiles as being native to more than a few counties in Texas, although you could no doubt purchase them in grass nurseries. 

The main point we want to make is that selecting another grass and another and another in pursuit of the perfect lawn is not going to work. You need to rethink your lanscaping, putting shade tolerant plants in the shade, mulching bare areas over the tree roots, and confining the lawn grasses to areas with plenty of sun. If you let the plants do what they want to do naturally, you will spend less money on water, fertilizer and plants, spend less time trying to coax them into viability, and have the opportunity to enjoy your valuable trees and their shade.