The short answer: Effective weed control in Texas comes down to two things: preventing weeds before they sprout and killing the ones that break through. The best approach combines pre emergent herbicides applied in January and September with targeted post emergent treatments throughout the growing season.
Here’s what works for most Texas lawns:
Quick overview:
- For annual weeds like crabgrass: Apply pre emergent before soil temperatures reach 55 degrees in late winter
- For broadleaf weeds like dandelions and clover: Use selective post emergent herbicides when weeds are actively growing
- For tough perennials like nutsedge: Apply specialized herbicides in late spring through summer when sedges are most vulnerable
The key to winning the weed battle isn’t reacting to problems after they appear. It’s staying ahead of weeds with properly timed treatments throughout the year. Keep reading to learn exactly when and how to tackle every type of weed common to Texas turfgrass.
The Complete Weed Control Approach: Our 8 Round Treatment Program
At Lawn Squad of North San Antonio, weed control is built into every round of our treatment programs. We don’t treat weeds as an afterthought. We design our entire approach around preventing and eliminating them.
Our programs include broadleaf weed control in all eight treatment rounds, pre emergent applications in rounds 1, 2, 7, and 8, and specialized sedge control during the summer months when nutsedge is most active.
This systematic approach works because it matches the life cycle of weeds. Different weeds germinate at different times, and each type requires specific products applied at specific times to be effective.
Even if you prefer to handle weed control yourself, understanding these timing principles will dramatically improve your results.
Why Weed Control Matters More Than Most Texas Homeowners Realize
Weeds aren’t just ugly. They actively harm your lawn by competing for water, nutrients, and sunlight. A lawn with heavy weed pressure will always struggle, no matter how much you water or fertilize.
Here’s what happens when weeds take over:
They steal resources. A single dandelion plant can spread roots three feet deep, pulling water and nutrients away from surrounding grass. Crabgrass can produce 150,000 seeds per plant per season. Nutsedge spreads through underground tubers that can survive for years in the soil.
They create bare spots. When annual weeds like crabgrass die in fall, they leave behind bare soil that erodes over winter and fills with new weeds in spring. This cycle gets worse every year if not addressed.
They indicate underlying problems. Heavy weed pressure often signals issues with soil health, drainage, mowing height, or irrigation. Weeds thrive in conditions where turfgrass struggles.
The good news is that a thick, healthy lawn is the best weed prevention. Grass that’s properly fertilized, watered, and maintained crowds out weeds naturally. Our approach focuses on building lawn health while simultaneously attacking weeds from multiple angles.
Pre Emergent Weed Control Guide for Texas Lawns
Pre emergent herbicides are the foundation of any effective weed control program. They create a chemical barrier in the soil that kills weed seeds as they try to germinate.
Step 1: Understand What Pre Emergents Do
Pre emergent herbicides don’t kill existing weeds. They prevent new weeds from sprouting. Think of them as a shield that stops the next generation of weeds before they become a problem.
This means timing is everything. Apply too late and weed seeds have already germinated. Apply too early and the product breaks down before peak germination.
Why this matters: A properly timed pre emergent application can prevent 80% to 90% of annual weeds like crabgrass, goosegrass, and annual bluegrass.
Step 2: Time Your Spring Application
In the San Antonio area, apply spring pre emergent between January 5 and February 16. The goal is to get product down before soil temperatures consistently reach 55 degrees, which triggers crabgrass germination.
Watch for these signs that it’s time:
- Forsythia bushes begin blooming
- Redbud trees start flowering
- Soil thermometer reads 50 to 55 degrees at a 4 inch depth
Why this matters: Crabgrass is the most common summer annual weed in Texas. Missing the pre emergent window means fighting it all summer long.
Step 3: Apply a Second Spring Application
One pre emergent application provides about 8 to 12 weeks of protection. For season long control, apply a second round in mid February to extend the barrier through late spring.
Our ELITE and PRO programs include pre emergent in both Round 1 (January) and Round 2 (February) for this reason.
Step 4: Time Your Fall Application
Fall pre emergent targets winter annual weeds like annual bluegrass (Poa annua), henbit, and chickweed. Apply in mid September before soil temperatures drop below 70 degrees.
These weeds germinate in fall, survive winter, and explode with growth in early spring. By then, it’s too late for pre emergent. You’re stuck pulling them by hand or using post emergent herbicides.
Critical warning: Pre emergent herbicides prevent ALL seeds from germinating, including grass seed. If you plan to overseed your lawn, you cannot use pre emergent for at least 8 to 12 weeks before or after seeding.
Post Emergent Weed Control Guide for Texas Lawns
Post emergent herbicides kill weeds that have already sprouted. They’re your second line of defense when weeds break through the pre emergent barrier or when you’re dealing with established perennial weeds.
Step 1: Identify the Weed Type
Different weeds require different products. Before you spray anything, figure out what you’re dealing with.
Broadleaf weeds have wide leaves with visible veins. Examples include dandelions, clover, chickweed, henbit, and dollarweed. These are the easiest to control with selective herbicides that kill broadleaf plants without harming grass.
Grassy weeds look like grass but aren’t desirable turf. Examples include crabgrass, dallisgrass, goosegrass, and annual bluegrass. These are harder to control because products that kill grassy weeds can also damage your lawn.
Sedges look like grass but have triangular stems (remember: sedges have edges). Nutsedge is the most common in Texas. It requires specialized products because it’s not a true grass or broadleaf.
Step 2: Choose the Right Product
For broadleaf weeds: Use a selective broadleaf herbicide containing 2,4 D, dicamba, or triclopyr. These kill broadleaf plants while leaving grass unharmed when applied correctly.
For crabgrass: Once crabgrass has more than two tillers (side shoots), pre emergent won’t help. Use a post emergent crabgrass killer containing quinclorac or fenoxaprop.
For nutsedge: Standard broadleaf herbicides don’t work on sedges. Use products containing sulfentrazone or halosulfuron, which target sedges specifically.
Step 3: Apply at the Right Time
Post emergent herbicides work best when weeds are actively growing. For most broadleaf weeds, this means spring and fall when temperatures are between 60 and 85 degrees.
Avoid applying post emergent herbicides when:
- Temperatures exceed 90 degrees (causes grass stress and poor results)
- Rain is expected within 24 hours (washes product off leaves)
- Lawn is drought stressed (increases risk of turf damage)
- Wind speeds exceed 10 mph (causes drift to desirable plants)
When to Avoid Post Emergent Application
During summer heat waves: High temperatures stress both weeds and grass. Herbicide applications during extreme heat can damage your lawn more than the weeds. Wait for a cooler stretch.
On newly seeded lawns: Most post emergent herbicides can damage young grass. Wait until new grass has been mowed at least three times before applying broadleaf weed control.
Step 4: Apply Correctly for Best Results
Post emergent herbicides are contact killers. They need to coat the weed’s leaves to be absorbed into the plant. For best results:
- Apply when weeds are dry (morning after dew evaporates)
- Use enough product to wet leaves but not drip off
- Don’t mow for 24 to 48 hours before or after application
- Don’t water for 24 hours after application
How to Identify Common Texas Weeds
Knowing what you’re fighting is half the battle. Here are the weeds we see most often in North San Antonio, Boerne, Bulverde, and surrounding areas.
Crabgrass: Low growing grassy weed that spreads outward in a star pattern. Light green color, coarse texture, and grows aggressively in summer heat. Dies with first frost, leaving brown patches.
Nutsedge (Nutgrass): Looks like grass but grows faster and has a yellow green color that stands out. Triangular stems if you roll them between your fingers. Extremely difficult to control because it spreads through underground tubers.
Dandelion: Yellow flowers that turn into white puffballs. Deep taproot makes hand pulling ineffective unless you get the entire root. Seeds spread on the wind.
Clover: Low growing with distinctive three leaf pattern. White or pink flowers attract bees. Spreads through runners and seeds. Some people consider it desirable, but it crowds out grass.
Henbit: Winter annual with square stems and pink to purple flowers. Very common in Texas lawns during spring. Dies in summer heat but drops seeds for next year.
Dollarweed (Pennywort): Round, shiny leaves about the size of a silver dollar. Thrives in wet, overwatered areas. Controlling moisture often controls this weed.
Dallisgrass: Clumping perennial grass with coarse texture and tall seed heads. Forms unsightly bunches that stick up above mowed lawn. Very difficult to control without damaging surrounding turf.
What About Organic Weed Control?
For homeowners who prefer to avoid synthetic chemicals, organic options exist but require different expectations.
Corn gluten meal acts as a natural pre emergent. It releases compounds that inhibit root development in germinating seeds. Effectiveness is lower than synthetic pre emergents (50% to 60% control vs. 80% to 90%), and it requires higher application rates.
Vinegar based herbicides work as post emergent contact killers. They burn the foliage of weeds but don’t kill roots. Perennial weeds typically regrow. Multiple applications are needed.
Hand pulling remains the most effective organic method for small infestations. Remove weeds when soil is moist, and get the entire root system. This works well for dandelions and other taproot weeds.
Lawn Squad offers an organic program for customers who prefer this approach. It combines organic fertilizers with weed control methods that minimize synthetic chemical use while still delivering results.
The honest truth is that organic weed control requires more patience and typically achieves less complete control than conventional methods. But for many homeowners, that tradeoff is worth it.
Common Weed Control Mistakes Texas Homeowners Make
We’ve treated thousands of lawns across Bexar, Kendall, and Comal counties. These are the mistakes we see most often.
Mistake 1: Missing the Pre Emergent Window
This is the single biggest mistake. Once crabgrass or other annual weeds have germinated, pre emergent is useless against them. You’ve lost your best opportunity for easy control and now face a summer of battling visible weeds.
Mark your calendar for early January and mid September. These are the two most important weed control dates of the year.
Mistake 2: Using the Wrong Product
Spraying broadleaf weed killer on nutsedge does nothing. Using a non selective herbicide like glyphosate (Roundup) kills your grass along with the weeds. And using the wrong concentration can either fail to kill weeds or damage your lawn.
Always identify the weed first, then choose a product specifically labeled to control that weed in your grass type.
Mistake 3: Spraying in Hot Weather
When temperatures exceed 90 degrees, most herbicides become less effective and more likely to damage turfgrass. The weeds are stressed and not actively growing, so they don’t absorb the product well. And your grass is already struggling with heat stress.
Wait for temperatures below 85 degrees for best results.
Mistake 4: Expecting Instant Results
Post emergent herbicides take time to work. Most broadleaf weeds take 7 to 14 days to fully die after application. Nutsedge can take 3 to 4 weeks. Dallisgrass may require multiple applications over several months.
Patience is essential. Reapplying too soon wastes product and increases the risk of turf damage.
Mistake 5: Neglecting Lawn Health
The best weed control is a thick, healthy lawn that crowds out weeds naturally. If you’re constantly fighting weeds, look at the bigger picture. Are you mowing too short? Watering incorrectly? Skipping fertilization?
A lawn that’s properly fed, watered, and maintained has far fewer weed problems than one that’s stressed and thin.
Pre Emergent vs. Post Emergent: Which Should You Choose?
Pre emergent herbicides prevent weeds before they appear. They’re invisible protection that stops problems before they start. Drawbacks: They require precise timing, don’t help with existing weeds, and prevent grass seeding.
Best for: Annual weeds like crabgrass, goosegrass, and annual bluegrass. Also effective against winter annuals like henbit and chickweed when applied in fall.
Post emergent herbicides kill weeds you can see. They’re reactive treatments that address visible problems. Drawbacks: Weeds must be present and actively growing, multiple applications may be needed, and results take time.
Best for: Perennial weeds like dandelions, clover, and nutsedge. Also necessary for any weeds that break through pre emergent barriers.
The smart approach: Use both. Pre emergent in January, February, September, and October prevents the majority of weed problems. Post emergent throughout the growing season handles whatever breaks through. This is exactly how our lawn care programs are structured.
Your Texas Weed Control Calendar at a Glance
Winter and Early Spring (January through February)
| Target Weeds | Treatment | Timing |
|---|---|---|
| Summer annuals (crabgrass, goosegrass) | Pre emergent | Apply before soil reaches 55 degrees |
| Winter annuals (henbit, chickweed) | Post emergent | Treat actively growing weeds |
| Broadleaf perennials | Post emergent | Treat when temperatures are above 50 degrees |
Spring and Early Summer (March through May)
| Target Weeds | Treatment | Timing |
|---|---|---|
| Emerged broadleaf weeds | Post emergent | Treat when weeds are actively growing |
| Nutsedge | Specialized sedge control | Begin treatment when sedge emerges |
| Crabgrass escapes | Post emergent crabgrass killer | Treat young plants before they tiller heavily |
Summer (June through August)
| Target Weeds | Treatment | Timing |
|---|---|---|
| Nutsedge | Specialized sedge control | Continue treatment through peak growth |
| Broadleaf weeds | Post emergent | Apply during cooler morning hours only |
| Dallisgrass | Spot treatment | Multiple applications needed |
Fall (September through November)
| Target Weeds | Treatment | Timing |
|---|---|---|
| Winter annuals | Pre emergent | Apply before soil drops below 70 degrees |
| Fall germinating broadleaf | Post emergent | Treat actively growing weeds |
| Perennial broadleaf | Post emergent | Excellent control window as weeds store energy |
The Bottom Line
Effective weed control in Texas isn’t about finding a magic product that kills everything. It’s about understanding weed life cycles and timing your treatments to match.
Key principles to remember:
- Pre emergent applications in January and September prevent most annual weeds
- Post emergent herbicides work best on actively growing weeds in moderate temperatures
- Different weed types require different products: broadleaf killers for dandelions, sedge killers for nutsedge
- A thick, healthy lawn is your best long term weed prevention strategy
- Patience matters because most herbicides take one to three weeks to show full results
Follow these principles and you’ll spend less time fighting weeds and more time enjoying your lawn.
Let Lawn Squad Handle It For You
Weed control is one area where professional expertise really pays off. Knowing which products to use, when to apply them, and how to combine weed control with fertilization and other treatments requires years of experience.
Our programs are designed to attack weeds from every angle throughout the year.
ELITE Program includes:
- Broadleaf weed control in all 8 treatment rounds
- Pre emergent applications in Rounds 1, 2, 7, and 8
- Sedge suppression during peak nutsedge season (Rounds 4 through 6)
- Surface insect control that prevents pest damage which weakens grass and invites weeds
- Fertilization that builds thick turf to naturally crowd out weeds
- Unlimited service calls for breakthrough weeds between scheduled visits
Stop fighting the same weeds year after year. Let us handle the timing, product selection, and application while you enjoy a lawn that’s actually weed free.
Contact Lawn Squad of North San Antonio today at (210) 919-2420 or visit lawnsquad.com/contact-us to get a free quote and finally win the war on weeds.
