I wonder if the climbing Giant Nasturiums will grow well in central Texas?
They don’t mind the heat, but keep them well watered. You can probably get them to self-sew down by you. (That doesn’t work up here, but I love them, anyway!)
I start flats of them, to get a jump-start. I have Strawberries and Cream, Queen of Sheba, Black Velvet and Carribean Cocktail this season. It’s not a garden without them. :)
http://www.gardeningtipsnideas.com/2006/11/growing_nasturtiums.html