Any broadleaved lawn weed killer should work perfectly well on violets. They ARE tricky to remove manually.

Thank you all for your answers. The photos in the link kimmq provided look exactly like a what I have.

Native, edible, host plant for various fritillary butterflies.

http://www.illinoiswildflowers.info/savanna/plants/cm_violet.htm

Thanks Tiffany. The flowers are nice, but I prefer them to not be in my lawn! They are currently taking over. As far as butterflies, I am focusing on creating a Monarch habitat. I have a good number of native milkweed seeds stratifying in the frig right now and will be sowing them the first week of April. Wish me luck!

In my experience few of the plant poisons, herbicides, available to homeowners are effective at controlling wild violets. Not even the glyphosates do well with this very hardy plant.

Unfortunately, these wild violets grow best in the same soils that a good healthy turf needs, neutral soil pH, a soil well endowed with organic matter that is evenly moist but well drained. However, I see them growing quite well in about any soil. Sometimes I see references to shade, but I see them growing quite well, too, in full sun.

kimmq is kimmsr

Because of their long tap root and resulting significant carbohydrate stores, violets will require repeated applications of any herbicide. But they are effectively controlled using any sort of lawn broadleaved weed killer (typically some mix of 2, 4-D and dicamba - NOT glyphosate) and now is the time to begin the first application. btw, lawn weed killers will not damage the lawn when used properly according to label directions.

Happy to share. Violets aren't a butterfly host plant because of their flowers. Host plant means the caterpillars eat the plants. (Just like monarch caterpillars will eat your milkweed plants, the only plants they can eat.) A functioning butterfly garden should have host plants as well as nectar plants, and no herbicides or pesticides should be used around them. It would be a terrible cruel irony to attract some of the few monarch that are left and then poison them.

The notion of a "lawn" as 1 kind of plant is a new phenom in the last century, aided by the fabricated concoctions that kill somewhat selectively. It's a crime against nature to try to kill the violets so the grass can grow, but one we have been brainwashed to believe is an OK or even good thing to do. There is nothing about violets that make them unsuited to being in a lawn, they're soft, green & can be mowed. I consider my entire property to be a butterfly garden.