One of the key ways to keep weeds out of your lawn is to prevent them from growing there in the first place. That’s why you should consider using a preemergence herbicide early this spring. A preemergence herbicide doesn’t stop the weed seeds from germinating, but by providing a chemical barrier at the soil surface, it stops them before they “emerge” (thus, preemergence). Preemergence products are often sold in spring as crabgrass preventers, since they control summer annual grassy weeds like crabgrass and goosegrass.
The time to apply preemergence herbicides is around the time that dogwoods begin to bloom (early March in southeastern North Carolina). Unless you have a fescue or bluegrass lawn, avoid “weed and feed” products, since applying fertilizer too early to a warm-season lawn can increase the risk of cold damage from late freezes.