On the USDA zone part of your question, it depends where in Texas you are. Dallas for example is zone 8a, Austin is 8b, Houston is 9a and Brownsville is 9b. These zones are only good for general guides. Your local micro-climate also affects it. For example I am technically in a zone 8b equivalent but one part of my garden has been specially designed to give me just a few degrees more in winter, so that is more like 9a. Hope this gives you some idea but it just isn't as simple as all that.