1 The stronger and thicker you can get your lawn, the less chance violets will stand to spread. 2  Seed your lawn. 3  You can either over-seed during a core aeration or slice-seed areas to help them fill-in with new turfgrass.4  Stay on top of things. 5  It may take a couple years to really get a handle on a big crop of violets.ollow these basic principles to win the war on violets: 1  Use the right herbicides. 2  Create an environment that is best for your lawn. 3  Fill in the thin or bare areas. 4  Stay on top of things.