Between June 1st and September 30th, Florida experienced most of its annual rainfall.  We love the rain because the plants are naturally irrigated, but sometimes, we wish to put the rain on a timer. Unfortunately, the rain also irrigates the weeds, which tend to grow faster than our turfgrass, making it look unsightly.

I have many weeds in my Bahia lawn, but my lawn has no weed problem. I learn to tolerate some imperfection, and if it’s green, I mow. If your lawn is infested with weeds, it is best to mow before it produces seeds. If you mow a lawn with seeded weeds, it’s good practice to bag and remove the clippings from the site. Not removing clippings means replanting the seeds and increasing the weed problem.

If you are considering applying a post-emergence herbicide, it is best to use it when weeds are in the juvenile stage and are more susceptible. Mature weeds are more difficult to control, may require more than one application, and often take more herbicides because mature weeds have a larger surface area.

In many cases, herbicides are applied, unable to control the intended weeds. Here are some of the possible reasons why herbicides fail. The weed was not correctly identified and was not listed on the herbicide label. Not following label instructions. Timeliness of application, meaning that the weed was very mature, and the herbicide worked best on young plants. There was rainfall or irrigation applied hours after herbicide application, inadequate herbicide programs, meaning too few applications, and poor herbicide choice, meaning using a herbicide with poor efficacy. Ensuring proper coverage and equipment calibration is essential for excellent weed control. It’s important to note that repeatedly using the same herbicide or herbicides with the same mode of action may result in herbicide resistance. Also, follow the label directions for mowing before or after herbicide application.

Applying pre-emergence emergence herbicides at the appropriate time is the best control for annual weeds. Apply pre-emergence late winter (January-February) to control annual summer weeds, depending on your location. To control annual winter weeds, apply pre-emergence when the temperature is around 55 degrees Fahrenheit consistently for about five days.

For more information on weeds and any other horticulture questions, contact Grantly Ricketts, UF/IFAS Extension Agent, at or by phone at 772-462-2847.

by Grantly Ricketts

Source: UF/IFAS Pest Alert

Note: All images and contents are the property of UF/IFAS.

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