Tennessee Smart Yards Native Plants
A comprehensive database of Tennessee native plants
Wild Petunia
 Photo Courtesy Katie Walberg  Photo Courtesy Katie Walberg |
Wild PetuniaRuellia humilisFull sun, medium to dry moisture level, any soil including clay, slightly acid to neutral pH. 1 ft. height, blooms over a long period in summer, purple flowers, rapid re-seeder.Germination Code: C(70)Native Region: Central Basin and Valley and Ridge Provinces and very lightly elsewhereWild petunia has an attractive flower and can make a good groundcover. However, plants can shoot seeds up to 10 feet away so it can be invasive.flower;sun;medium;clay |
Tennessee Smart Yards Native Plants 
That last word, “invasive” nails it on the head for me. I have these plants planted in an area with a small retaining wall along the driveway. This summer I had so many seeds shooting into the driveway, I could have vacuumed them up, packaged and sold them. In my experience this plant is too competitive to be used in a bed with other shorter plants because it will drown them out. In the right place this could be a great plant. I imagine that place would be a site where you need quick coverage and want one species as a groundcover. It seems to be a tough little plant.
I would like to add a quick update to my March 1, 2013 post. I have discovered that the plants in the area that I described have been successfully shooting seeds into the lawn. Even though we have mowed every 6-7 days all summer long (especially with all the rain this summer), we have the darned things coming up in the lawn and blooming! It doesn’t seem to matter that they get cut back every week and only get a few inches tall before they are cut again. I do still think it is a pretty plant but, man, they are tough! If I had it to do over again, I would never plant them because I don’t have the kind of space where they would be most useful—a large area needing fast, dependable coverage that isn’t near something you care about.