Ruellia humilis, Wild Petunia

 

Wild Petunia is extremely rare in Minnesota, possibly found in only one location, near the St. Croix. Yet, it's likely to be found in native plant gardens across Minneapolis-St. Paul. You'll find complaints about its spread and praise for the way it fills up a space between other native plants. This will be your call -never plant something known to spread easily without creating competition for it by planting several other species. Another tip: if you plant Ruellia humilis, as a plug or mature plant, make sure its competition is planted similarly -don't count on seed to do the competing. Is lawn grass a good competitor? Probably not, so consider that some folks say it invades their lawn. 

While Ruellia humilis does well in our urban climate, it is a decidedly Central and Southern Midwestern species that, even where it did occur in Minnesota, did so less frequently. I imagine this planted with Butterflyweed, Large-flowered Penstemon, Side Oats Grama, Prairie Onion, and Round-headed Bush Clover.

Blooms: pale lavender with white, June to August

Height: 8 to 18 inches 

Conditions: sun to pt shade, medium to dry soil

 

A pretty large patch with no competition at the edge of lawn.