PlantFiles: Wild Petunia
Ruellia humilis

I was intrigued by the idea of a perennial petunia. I planted a couple and have had them now for a few years. They are very low maintenance and they're beautiful when they bloom. I do wish they had a longer bloom period, however.

This plant is found mostly in the cracks and crevices around the patio and walkways. It's a nice plant - just appears in inconvenient places. I was spraying some Roundup on some grass and sprayed some on a few of the (believed to be) wild petunias. In a few seconds I started hearing some very noticeable popping sounds. At first I thought it was some sort of snapping bug or grasshoppers that the spray had irritated. Something was even hitting me and it was ricocheting off of things nearby. When I looked closely I found that the seed pods on this plant were popping open and ejecting a seed. They were traveling several feet. I assume that the moisture in the spray must have made the plant react as if to rain and thus spread its seeds. I have not seen this interesting feature reported in my readings about wild petunias. Has anyone else observed this or am I actually seeing a similar but different plant?

Update 8/13/2011: After extensive research, I have found that the plant that I have commented on is actually ruellia nudiflora or purple wild petunia. I will copy my comments to that page.

This is a tough plant! I grew mine from seed last year and I wasn't good about watering them when the second half of our summer was unusually dry. They toughed it out for a long time, but eventually withered away and, I thought, died. I was mad at myself because I really liked them and resolved to grow more for this year, which I did. I was stunned to discover that they returned this spring and I'm happy I have my new plants to add to last year's. I should note that even as first year perennials they bloomed. That they also survived my lack of care and returned tells you how tough they are.

This is a pretty plant which grows wild on the edges of the woods and pops up here and there in the lawn with it's pretty "burple" flowers. I have a few volunteers I treat with extra care, and these are growing well & flowering non-stop. They remind me, in form & looks, of another plant I have, "Blue Bells" Browallia. These plants apparently seed, and also tolerate high humidity & temperatures, as well as frost. They also are drought-tolerant. They grow in the sandy, dry, shaded mixed wooded edges as well as out in the full sun where I live.

Native in the US from TX to MN, east to PA, south to FL. Endangered in MD, PA, and WI, threatened in NC and MI.

This is a noxious evergreen weed in my yard ~ I fight it in every flowerbed and between bricks on the patio! It is pretty in bloom and the foliage is nice; if it were just more easily controlled.

Wild Petunia Ruellia humilis is native to Texas and other States.

In St. Louis this reseeds but does not last the winter. Hardy, warm season, full sun, annual.

Talk about an easy-to-grow plant. This grows wild in the cow pasture behind our property. The blooms don't have the staying power of the annual petunias but the fact it's a perennial and virtually care-free make up for the lack of profuse blooms.

Low spreading perennial for dry shade. Misty lavender miniature petunia-shaped blooms throughout summer. Flowers slightly more than 1" acoss. Prefers high heat and humidity. Will reseed occasionally.