To completely clear an area of plant life, including both grass and weeds, a general weed killer, such as Round-Up or Hi-Yield KILLZALL, will help you get rid of unwanted vegetation, yet you can replant the area in as little as seven days. These products are absorbed by the plant's leaves, and from there are taken throughout the entire plant and down into the roots. They work by stopping the formation of amino acids the plant needs for nourishment, so it isn‘t a quick kill, but it‘s a very effective one. It must land on the leaves, or stems, or the exposed roots, flowers or fruits of a plant in order to kill it. If you are spraying weeds around plants that you want to keep, protect the valuable plants with a sheet of plastic or cardboard, or cover the plant with a cardboard or plastic container if the plant is small enough. Avoid spraying at times when there is a breeze, because air movement could cause spray drift and the product could land on something you don't want to kill. Plants need to be dry before KILLZALL is applied in order to be effective. The weeds or grasses have to be up and actively growing. Spraying done early in the spring may take weeks to kill because the temperatures are too low. Temperatures between 60 and 85 degrees are necessary for the best and quickest results. If the temperatures are cooler, between forty-five and sixty, Ferti-lome Weed Free Zone is very effective on weeds, but it won’t kill grass. KILLZALL is also the easiest way to renovate a lawn, one that you want to start completely over on. Spray the area to be renovated evenly. Wait seven days. Using a dethatching machine, go over the dead grass thoroughly. The dethatcher will remove a lot of the dead grass and also slice holes in the soil under the sod, giving a place for the new seed to start growing. Seed the new grass directly on top of the old dead grass and water it in. The old grass will act as a protective mulch and help the grass seeds get a good start. Be sure to fertilize your new lawn with 16-16-16 until it is six months old, and make sure your new lawn doesn’t dry out.