Extension

The fall season has arrived in Oklahoma. It’s the season for roasting marshmallows over the firepit, cheering on your hometown football team under the Friday night lights and retrieving a favorite hoodie from the closet. It’s also time to control pesky winter annual weeds.

 

Just when homeowners are finishing lawn mowing for the season, it’s time to switch gears and implement a plan for controlling winter annual weeds such as henbit, chickweed and annual bluegrass. Although these weeds are short-lived, they detract from the landscape. They also compete with desired plants for water and nutrients.

 

Timing is key when it comes to controlling winter annual weeds. Now through mid-October is the best time to enact control measures. Control is much more difficult once the weeds mature and flower in the spring. Apply preemergence herbicides before the expected germination time of the weeds. Once applied, be sure to water in the herbicide for best results. However, homeowners who plan to seed any areas this fall should not apply preemergence herbicide.

 

Postemergence herbicides can be effective on small, actively growing weeds, but not so much once the weeds flower. Fall is an excellent time to apply postemergence broadleaf herbicides to existing weeds and some of those early germinating winter annuals because the cooler daytime temperatures in the fall are ideal for application of these products. Winter annuals that make it through the winter can be controlled in late winter/early spring with postemergence herbicides.

 

Homeowners can also take the cultural approach to weeds. Maintaining a healthy, dense lawn through proper mowing, fertilization and overseeding will help. A vigorous stand of grass will shade the soil while reducing weed establishment.

 

Consider combining cultural and chemical strategies for a more comprehensive, long-term approach. Relying solely on herbicides may lead to resistance or incomplete control.

 

Consumers have a lot of choices for herbicides at the local garden center. Be sure to read the label as some are just for turf areas, while others are for both turf and ornamental areas. Find the one that matches your needs, and as always, read and follow the application directions on the label.