Kill broadleaf weeds without killing the grass by using a post-emergent herbicide. If only a few weeds are present, pulling them by hand offers a chemical free method of control. Regardless of the method you choose, encourage a healthy, weed-free lawn by fertilizing, watering and mowing on a regular basis.
Apply post-emergent herbicides once the grass turns green again after the dormant season. Follow the label directions carefully to prevent damaging the rest of the lawn and polluting streams with runoff water. The roots of the weeds transport the chemicals from the herbicide throughout the plant and cause it to die. Some of these herbicides are mixed with fertilizer to encourage growth of the desirable lawn grasses.
If the weed problem is just beginning and you want to avoid use of herbicides, pull the weeds while leaving the grass intact. If the weeds have long roots, invest in some weeding tools to help remove them without damaging the surrounding grass. When weeding, remove as much of the root as possible, as some weeds regenerate from a small portion of root.
Lush and healthy lawns help prevent weeds from growing. Encourage healthy grass by mowing regularly. Do not remove more than one-third of the height of the lawn when mowing. Avoid watering every day, but irrigate on a regular schedule that encourages the roots of the grass to grow deep into the soil.