My blogging friend Gail at Limestone and Clay has complained about the lackluster performance of her Ruellia. I must not have been fully awake when I read that post, because I never got past the words "Wild Petunia" and "Ruellia" to the important word "strepens." I responded in a comment that hers must not be happy because my Ruellia humilis blooms profusely. Ah, the difference one Latin word makes.
Not only does this native plant pump out the lavender trumpets, it does so on the edge of the blacktop driveway, with no supplemental water and no mulch. It does this for a very long time, too. Even when not in flower, its fuzzy foliage is attractive. No, this plant isn't perfect. The flowers last only a day, and its seedlings appear far from the mother plant. I'm frequently pulling them out of the lawn. But it suffers no serious pest or disease problems, never needs to be deadheaded and thrives on neglect. So, Gail, how about giving this Wild Petunia a try? I'll bet you'll like it better.
edit. 7/13/08 D'oh! I'm such an airhead. I typed "humulis" instead of "humilis." I corrected the error. I apologize for any confusion.