In the summer, blue flowers are a necessity. They seem to cool things off psychologically. I have Blue Globe Thistle (Echinops) in my front beds. I have begun to let them seed so that I will have more each year.
This is another blue flower that my garden cannot do without. It is a native plant to Texas that is carefree. This variety of Mealy Sage (Salvia farinacea) 'Henry Duelberg' has been name a Texas Superstar by Texas A & M. It blooms well into fall. For more information on this great Texas plant go to: http://www.plantanswers.com/salvia.htm