Preemergence herbicides help prevent weed growth in turfgrass by stopping weed seed germination. It is essential to know the difference between selective and nonselective herbicides and to understand how application timing contributes to the effectiveness of weed control efforts.
Hot, sunny days with daily rain showers are a few months away. With spring and summer comes the unwanted and vigorous growth of weeds in turfgrass.
What does this mean? It means that the time for weed control is now.
Most homeowners are already familiar with standard methods of weed control, including mowing, hand pulling, and smothering. In this blog, we take a closer look at the fourth method of weed control: herbicides.
Applying preemergence herbicides stops weeds in turfgrass before they grow. Read this article to understand what preemergence herbicides are and how they work, the different types and purposes of herbicides, and when to apply the appropriate herbicide to save yourself the work and frustration of managing lawn weeds.
What are Preemergence Herbicides?
Preemergence herbicides are chemicals that keep weed seeds from germinating and weeds from growing. The use of preemergence herbicides is a proactive and preventative method of turfgrass weed control. They are generally used to prevent annual broadleaf weeds and annual grasses. Preemergence herbicides must be applied before weed seeds germinate to be effective.
Know Your Herbicides
When determining the appropriate herbicide to use for your weed situation, it is critical to have a thorough understanding of the differences between herbicide types.
Most herbicides fall into the category of selective herbicides, which control weeds without harming turfgrass. Selective preemergence herbicides may be applied to an entire patch of turfgrass and will stop the germination of weeds in that section without affecting the growth of the grass. Of course, you must select an herbicide based on the species of your turfgrass.
Nonselective herbicides kill all plants they contact regardless of plant species. Nonselective preemergence herbicides will stop the germination of all vegetation seeds (weeds and otherwise) before it happens. This is an excellent option for places that need to be completely vegetation-free.
Timing is Everything
Due to the narrow window of time in which preemergence herbicides do their job effectively, Florida homeowners need to be aware of the life cycles of the weeds they wish to target.
These timelines differ slightly across the state. In general, homeowners should plan to apply preemergence herbicides by February 1st in South Florida, by February 15th in Central Florida, and by March 1st in North Florida. Pay attention to the weather, however. You may need to apply these herbicides sooner if daily temperature highs reach 65℉-70℉ for a consecutive four or five days.
Plan to Water In and Reapply
Regardless of which preemergence herbicide you choose, there are two things you can do to ensure the application is successful.
First, make sure to water either before or after the herbicide application. Watering is necessary to activate the preemergence herbicide.
Second, plan for reapplication of the herbicide. Most herbicides will remain active for 6-12 weeks after the initial application, so expect to reapply every 6-9 weeks for weed control throughout the season.