Some pre-emergent products include the Weed Prevention Plus 25 lb bag and the Snapshot 2.5 TG Granular Pre-emergent Herbicide. For larger applications, shoppers may also buy the Andersons 19-0-6 Turf Fertilizer Pre-Emergent Herbicide in a 50 lb bag.
Pre-emergent products are activated on the topmost layer of soil, where weeds sprout most frequently and prevent other plants from growing. These products help the seed germinate and then kill the young sprout before it has the chance to spread over the garden. Both granular and liquid solutions are available, and the pre-emergent remains effective in the soil for weeks at a time.