Flower Mound Lawn Mowing

What You Need to Know About Pre-Emergent & Post-Emergent Herbicides

~Flower Mound Lawn Mowing~

Fall will be here before you know it. And that means it’s time to apply pre-emergent and post-emergent herbicides to your lawn in Flower Mound, Highland Village, or Lewisville, TX.

As your Flower Mound lawn mowing service, we want your lawn to be healthy and dense. By controlling the weeds that pop up during the winter, you’ll allow your grass to come out of dormancy in the spring with no competition for space, water, or light.

Pre-emergent Herbicides

Pre-emergent herbicides, in granule or liquid form, are applied in early fall to kill weeds before they emerge from the ground. Ideally, you want to apply these weed killers before the temperature goes down to 55°F. You’ll need to reapply the pre-emergents again in January through March to keep weeds from surfacing in early spring.

Pre-emergents work well on grassy weeds, such as

  • Field sandbur

  • Goosegrass

  • Junglerice

  • Rescuegrass

  • Smooth crabgrass

  • Sprangletop.

Pre-emergents also work well on some broadleaf weeds and sedges, too. Read the labels to see what types of weeds your herbicide will target.

Post-emergent Herbicides

You use post-emergent herbicides on weeds that have already sprouted. As your Highland Village, Lewisville, and Flower Mound lawn mowing service, we recommend that you don’t mow your lawn before or after you apply post-emergents because you’ll want to get as much of the weed killer on your plants as possible. If we mow, and then you apply a post-emergent, it will only get a part of the weed and will not effectively kill the entire plant.

As your Highland Village, Lewisville, and Flower Mound lawn mowing service, we recommend that you use the following tips when applying post-emergent herbicides to your broadleaf weeds:

  • Use post-emergents only when the thermometer reaches 65°F - 85°F. That’s why we recommend using your post-emergents starting in the fall when daytime temperatures start to cool down. When temperatures rise above 85°F, you run the risk of burning your turf too.

  • Don’t use post-emergents if your lawn is super dry. You need adequate soil moisture for this type of herbicide to work. You’re also putting your lawn turf in danger when you use post-emergents on dry soil.

  • If you’re spraying post-emergent herbicides, check the weather forecast for Flower Mound, Highland Village, or Lewisville before you apply the weed killer. You want to make sure that there is no rain in the forecast for at least 24 hours after you apply the herbicide.

  • Don’t use these herbicides on windy days because you don’t want any of it to drift to your ornamentals.

  • Kill weeds while they’re young. You’ll need to regularly scout your lawn for broadleaf weeds so you spray them while they’re still emerging.

  • Reapply post-emergents every 10-14 days to keep broadleaf weeds under control.

You can buy pre-emergent and post-emergent herbicides at your local garden center or big box store. Follow all instructions for application and storage of extra herbicides. If you’re applying granules, make sure you irrigate your lawn up to ½” to activate the herbicide. And remember: Keep all herbicides and other chemicals away from children and pets.

Do you need a Highland Village, Lewisville, or Flower Mound lawn mowing service? Then call us at Main Street Mowing at 214-317-8301 or chat with us, Monday through Friday, from 9 a.m. to 5 p.m.


Clemson University Cooperative Extension Service, “Managing Weeds in Warm Season Lawns.”

McAfee, James, Ph.D. and Paul A. Bauman, Ph.D. “Herbicides for Weed Control in Turfgrass,” Texas A&M: AgriLife Extension.

McAfee, Maes, A. “Keys to Keeping Your Lawn Healthy Now…and Later.” Texas A&M, Dept. of Soil and Crop Sciences (1997).