Pre-emergent is specifically applied to control certain plant species before they get established and overtake desired areas of turf and/or landscape beds.
In turf areas, pre-emergent suppresses unwanted annual grasses, such as crabgrass, goosegrass and foxtail. Pre-emergent is designed to work best in healthy turf situations. Mowing at a minimal 3" length and proper seeding of bare/thin turf is needed for optimal success. Control severe edging. Nice, clean edges make our lawns look great, but when that edge becomes a 4-6" trench, our lawns become susceptible to crabgrass and weed infestation.
In landscape areas, pre-emergent suppresses many annual grasses and weed varieties, minimizing the need for pulling these pests by hand by as much as 90%. For pre-emergent to be the most effective, a proper layer of mulch must be maintained. If new mulch is applied, pre-emergent should be reapplied, as undesirable weeds and grasses can easily germinate in the new mulch.