The pre-emergent is used to control grassy weeds such as crabgrass and foxtail. Plus, it can also help with a select few broadleaf weeds, such as dandelions. Unfortunately, there isn’t a surefire way to prevent all weeds.

What weeds does pre-emergent prevent?

This herbicide is best used on grasses and broadleaf weed seeds, including crabgrass, dandelions, and plantains. Since pre-emergent herbicides only work on seeds, you can use Prodiamine to eliminate different types of invasive grasses in your lawn.

How long does pre-emergent take to kill weeds?

Reseeding Ater Using a Pre-Emergent If you pick a variety that kills grassy weeds, likely it will kill any new desirable grass seed as well. Most pre-emergence products lose effectiveness after about six to eight weeks, so wait at least that long before reseeding.