Roundup is a product made by the Scotts Miracle-Gro Company. It is designed to kill unwanted weeds and grass. It's active ingredient is glyphosate. Roundup Weed and Grass Killer comes in a concentrated form that needs to be mixed with water before you can apply it to your lawn. It is important that the mixing is done properly. Too little concentrate and the weeds won't die. Too much concentrate and you will damage your soil.
Measure out 5 tbsp. of Roundup Weed and Grass Killer for every 300 square feet of space you intend to cover. For example, if you need to kill 1,500 square feet of lawn, you would need 25 tbsp. of Roundup.
Measure out 1 gallon of water for every 300 square feet of space you need to cover. For example, if you need to cover 1,500 square feet of space, you would need 5 gallons of water.
Add your Roundup and water to a garden sprayer. Give the garden sprayer a shake to mix the two ingredients together.
Spray the weeds you want to kill until they are completely wet with the Roundup. Do this on a day when the outdoor temperature is above 60 degrees F.