As the weather starts to get colder, many people turn their focus to winter weeds.

The onset of fall weather gives weeds plenty of time to germinate and grow prior to the first frost so taking care of them quickly can prevent them from creating new weed seeds.

If you’re wondering whether it’s time to apply pre-emergent for winter weeds yet, use these tips to make sure you don’t waste any product.

Assess Current Conditions

Before you start thinking about pre-emergent weed killers, you’ll want to assess your lawn.

Are there weeds already growing in your lawn now? Are there certain spots that seem problematic that you might need targeted treatment for?

Grassy annual weeds must be treated before they have sprouted. Pre-emergent care is the only treatment option.

The time to apply pre-emergent herbicides is in September.

Non-grassy weeds, on the other hand, can be handled post-emergently by using a weed-killer spray.

The recommendation is to apply a pre-emergent herbicide in September and then apply a post-emergent in November if you still see any weeds.

Another pro-tip is that if you are treating your lawn for both grassy and non-grassy weeds; the weed killers must be applied separately. Do not mix them.

Identify Common Lawn Weeds

Knowing your enemy is a good step toward beating them. While there are dozens of different weeds that can invade your lawn, some are more common than others.

Knowing which weeds tend to plague your area will help you make better decisions about the pre-emergent application.

Looking for help with basic lawn care? Visit our Lawn Maintenance service page.

Annual Grassy Winter Weeds in North Texas

  • Rye Grass
  • fescue
  • Annual Bluegrass (Poa Annua)

Annual Broadleaf (Non-grassy) Winter Weeds in North Texas

  • Henbit
  • Clover
  • Chickweed
  • Burweed
  • Dandelions

After all, many homeowners choose pre-emergent herbicides because they don’t want an unsightly mess in their own yards! If it looks like something is spreading, then fighting back early can often help control these invaders later on.

Want to learn more? Check out Fall Broadleaf Weed Control.

Calculate Number of Weeds

The number of weeds you have is variable, but a safe estimate can be calculated by multiplying your square footage by 0.75 – 1 square foot per plant.

The square footage will vary depending on whether you have a big lawn or a small one and if you have any steep slopes that may contain fewer plants per square foot.

To keep things simple, let’s assume that 75% of your yard contains weeds with 25% being healthy grass/turfgrass. This means you have approximately 2 square feet of weeds per square foot of lawn.


The key to pre-emergent weed control is timing. If you get it right, your lawn will be covered in a blanket of dead weeds by spring.

To figure out if it’s time to apply pre-emergent, carefully walk your yard and look for new signs of winter weeds.

After you’ve applied the herbicide, wait 24-48 hours and then water your lawn deeply. This allows the weeds to thoroughly soak up the chemical. In addition to that, wait a couple of days to mow your lawn as well.

If this sounds like a lot of details to tend to, please visit our Fertilization and Weed Control service page to earn more about how Evergreen Lawn & Landscape can help keel your yard weed-free.

Final Thoughts

If you live in an area where winter weeds tend to take over your lawn, pre-emergent herbicides can be very effective at preventing these annual offenders from growing.

If you want to be safe and give your grass a fighting chance against weeds next season, it’s important that you apply pre-emergent early enough.

Choose your herbicide based on the type of grass you have. Pre-emergent weed-killers are specially designed for specific types of turf-grass.

All pre-emergent weed-killers work differently depending on their mode of action, so it’s important that you pay attention to any application time restrictions included with your product.