Smooth wild petunia grows wild in our habitat. We let it grow as it will because it serves as both a host and nectar plant, plus it is an attractive purple flower. Most importantly, it plays nice with other plants, meaning it is not prolific, aggressive, or invasive. We find that it needs very little care or attention in order for it to thrive. It prefers sun to part sun locations and doesn’t seem to mind our dry, clay soil.
As for it being used as a host plant, we’ve not noticed caterpillars feeding on it, but the Common Buckeye is a very stealth, secretive caterpillar.