Border grass isn't actually grass, but is in the lily family. It is also known as Liriope muscari. Border grass grows 10 to 18 inches high before recurving back toward the ground. It is a clump-forming plant and, as it matures, forms a continuous carpet that resembles shaggy lawn grass. Purple, violet or white flowers rise from the border grass in the summer months. If this plant is undesirable in your yard, it is easy to kill border grass using a non-selective herbicide, one that will kill any plant it comes into contact with. A common brand is Roundup and can be purchased at your local home improvement store.
Select a day with little wind to apply the non-selective herbicide. This will prevent the mist from drifting and killing desirable plants.
Mix the non-selective herbicide in your pump-up sprayer with water. Use a mixture of herbicide to water that is recommended on the concentrate bottle.
Spray the border grass until it looks "wet." It doesn't have to be drenched to work effectively.
Repeat the application in a week if there are still live areas of border grass. The dead border grass can then be removed by pulling it out, digging it out or letting it decay on its own.