@edgarblythe,
I like oleanders for many reasons, including the big ones, variety Queen Anne, as fire barriers - but in California they are in a lot of trouble from a bacterial disease spread by the glassy winged sharpshooter. I don't know if this is still true or not, since I haven't lived there or paid attention to whether that was somehow resolved for about seven years now. Says in Sunset Western Gardens (my western plant go-to bible, that there is no cure and that the disease is already serious in Arizona and Texas as well. But the book may be out of date in that regard.
Adds, you might ask at whatever state agriculture agency you've got going in Texas, or some other experts.