Pre-emergent Herbicides are the best way to reduce and eliminate weeds in your lawn. Pre-emergent Herbicides work by preventing weed seed germination. They create a layer that kills the weeds as they try to push past the top layer of soil.
The key to using pre-emergent herbicides is proper timing. There are two times of the year to apply your pre-emergent herbicides, the spring and the fall. When to apply these during that time period depends on your geographic location, you can contact your local county extension for the best times to apply. Most spring and summer weeds will germinate when the soil temperature at 4 inches down reaches about 52 to 55 degrees F for three or four consecutive days.
Some popular weeds that can be effectively controlled by pre-emergents include but are not limited to: