Ask any homeowner and they will likely tell you that weeds are the biggest nuisance in the yard. Most of the unwanted vegetation that populates our lawns in early spring actually gets its start in the fall and grows through the winter. The best way to control these winter lawn crashers is to stop them before they start with pre-emergent herbicides.
Pre-emergents work by killing seedlings after they germinate but before they emerge through the surface of the soil. Fall is prime time to keep winter weeds from ever breaking ground. Treating early ensures fewer weeds sprout, producing fewer seeds. With pre-emergent herbicide in the fall, your lawn’s weed population will be significantly reduced come spring.
When to Apply Pre-emergent Herbicide
Because these herbicides don’t work on seeds or on plants that have already emerged, timing is important. Too early and the seeds won’t have germinated. Too late and the plants will already be up.
- To control winter weeds like annual bluegrass, henbit and common chickweed, the University of Georgia (UGA) Extension Service recommends applying pre-emergent herbicide when temperatures fall between 65° and 70°F at night.
- For spring weeds like crabgrass and goosegrass, re-apply in February or March before soil temperatures reach 55°F.
How to Apply Pre-emergent Herbicide
Pre-emergent herbicides are available in both spreadable granules and sprayable options. Both need to be applied evenly across the lawn to work effectively. Most homeowners find the granules easiest to apply, but if you opt for the sprayable type, be sure to read the instructions carefully and mix accurately.
According to the UGA Extension Service, pre-emergents will not harm most established turf grasses, flowers, shrubs and trees. WARNING: Pre-emergent herbicides can severely damage newly seeded lawns. If you have a new or freshly over-seeded lawn, wait until the grass has been established for a full year before applying pre-emergents.
Year-Round Weed Control
Unfortunately, there is no magic bullet capable of eradicating the endless variety of insidious and persistent weeds. Although pre-emergents will not win every battle against every weed, they should be the mainstay of your arsenal. For the most common invasive weeds, applying pre-emergent herbicides twice a year will go a long way toward keeping your lawn beautiful year-round.