What herbicide do I have to use to kill wild violets?
What Herbicide to Use to Kill Wild Violet
Certified GKH Gardening Expert
This article will have additional info to help: https://www.gardeningknowhow.com/ornamental/bulbs/violet/kill-wild-violets.htm
You will want to use something that gets to the root of the plant or it will continue to pop up on you. Something like RoundUp or there is a Spectricide product as well. Cannot remember the name.... Just be sure it says that it will kill the root too and not just the top part of the plant.