When To Apply Pre-Emergent In Texas

lawn care schedule

when to apply pre-emergents in TexasWhen to apply pre-emergent in Texas? Many lawn and garden experts agree that you should apply a pre emergent herbicide in late winter/early Spring and also in late fall.  Texas weather is usually warmer in February than most other states in the US.

Why Apply Pre and Post-Emergents For Weed Control?

Proper fertilization, mowing, irrigation and soil aerating are all important factors creating a dense lawn, however sometimes weather events are beyond your control. This can cause the lawn to thin out or become over watered.

Applying a pre-emergent herbicide can serve as an insurance policy on the off chance the yard suddenly loses its luster.

Pre-emergent products kill weeds before they are able to grow above the soil. When is the right time to apply pre-emergent herbicides? Timing is very important! Apply pre-emergents just before the soil reaches 55+ degrees, just before the seeds begin to germinate in the soil.  Please follow the product label for mowing restrictions prior to and after herbicide applications as mowing can negatively impact the efficacy of the herbicide.

You can choose many different types of post-emergent products kill already-growing weeds. Note that some selective post-emergent will not harm foliage other than the target weed.  While non-selective will kill any plant it comes in contact with, including your grass. Please be refer to the product label for mowing restrictions prior to and after herbicide applications. Using a post emergent can be used as early as April in warm regions.

Are Pre and Post-Emergent Herbicides Safe for Kids and Pets?

Be cautious. Most pre and post-emergent products will state that they are safe for kids and pets. For the most part, that is true. The key thing to understand though is that herbicides are safe for kids and pets once they have been absorbed into the soil.

On long haired dogs, granules can get matted in a dog’s fur. They will then be absorbed their skin. Dogs will ingest liquid herbicides by sniffing and by eating the grass.

Children will absorb granules through their skin if they are laying or rolling in the grass. Kids can also ingest liquid herbicides through touching the grass. They can inhale the products just by breathing, if they are playing on the lawn.

This will cause vomiting, diarrhea, loss of appetite, and problems with sleeping. Rashes and burns have also been reported as a side effect.

Do not apply herbicides and then let your kids and dogs immediately out to play. Manufacturers recommend waiting at least 24 hours before using your lawn. Waiting 48-72 hours is the safest bet. This goes for both liquid and granular herbicide products.

When to Apply Pre-Emergents in Texas: Temperature, Weather and Herbicide Effectiveness

The reason that is recommended to apply pre-emergent herbicides when the soil temperatures are right around 55 degrees is because if the soil is too cold, the effectiveness of the herbicide will be reduced. If the soil temperatures are above 55 degrees, the herbicides could burn your lawn or crops. It will also evaporate before it can do its job.

Recommended application of post-emergent herbicides is when air temperature has reached between 65-85 degrees. The reasoning is the same, if it is too cold, the herbicide does not work as well. If it is too hot, the product will be evaporated before it can be absorbed into the soil.

Check weather forecasts before applying herbicides so that you are not bombarded with unexpected weather situations. For example, if you apply herbicides you do need water to get them working. Too much water, like a rainstorm will wash away or dilute products.

Suggested Herbicides for Fall / Winter

The Best Pre-Emergent Herbicides:

  • Prodiamine  is the longest-lasting, as well as most economical due to lowest application rates.

The Best Post-Emergent Herbicides:

  • Celsius Herbicide – Best for Warm-Season Grass Only (St. Augustine, Bermuda, Centipede, Zoysia)

Final Thoughts on When to Apply Pre-Emergent in Texas

As you have seen from this blog post, timing is critical when applying pre-and post-emergent products. Read product labels and adhere to manufacturer’s instructions.

Apply pre-emergent in Texas when soil temperatures are at 55 degrees. Plan to keep kids and pets off of lawn for a couple of days.


Picture of D Boone

D Boone

Love the outdoors. Unlucky in real estate but lawn and gardening I can excel at.

2 thoughts on “When To Apply Pre-Emergent In Texas

  1. Not really too up on things for treating your lawn so this is helpful. I’m hoping you can answer a couple questions. First, do you need to keep people off the grass for a certain amount of time after applying this pre-emergent treatment? For example, is it safe to walk on whether it’s people or pets? Also, will walking on it immediately after applying reduce its effectiveness. I’m thinking in terms of pets and kids who can’t resist a lawn. Second, you mention how the treatment should be applied before the lawn temperature reaches 55. What if you apply it beforehand and you get an unexpected warm spell? Does it have to be in the ground for a certain amount of time at a sub-55 degree temperature to be effective? Thanks.

  2. I live in the sandhills of LaVernia. I have some winter that typically germinate late December and January. I pull up some them before they are seeded. Small grass and small seeds. I use to know their names but don’t recall. What and when should I apply a preemergent. Your help will be greatly appreciated.

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