The best time to apply weed control in Tulsa depends on the type of weeds you’re fighting. For pre-emergent control of crabgrass and other summer weeds, apply in late February through early March when soil temperatures reach 55°F. For post-emergent control of active weeds, apply when temperatures are between 50 and 85°F and weeds are actively growing. For winter weeds like henbit and chickweed, apply pre-emergent in late August through September.
Let me break down exactly when and how to tackle the specific weed problems we face here in Tulsa.
Understanding Tulsa’s Two Main Weed Seasons
Living in northeastern Oklahoma, we deal with two distinct weed seasons that require different timing and strategies:
Spring/Summer Weeds (March-September): These include crabgrass, dallisgrass, spurge, goosegrass, and various broadleaf weeds like dandelions and clover. These warm-season weeds germinate when soil temperatures warm up in spring.
Fall/Winter Weeds (September-April): These include henbit, chickweed, poa annua (annual bluegrass), and rescuegrass. These cool-season weeds germinate in fall when temperatures drop.
The key to effective weed control isn’t just about what product you use—it’s about timing your applications to match our local weather patterns and soil conditions.
Pre-Emergent Weed Control: Your First Line of Defense
Pre-emergent herbicides prevent weed seeds from germinating. Think of them as creating an invisible barrier in your soil that stops weeds before they even sprout. This is always your most effective and economical approach to weed control.
Spring Pre-Emergent Timing (For Summer Weeds)
When to Apply: Late February through early March
The critical factor here is soil temperature, not air temperature. You want to apply pre-emergent when soil temperatures reach 55°F for three consecutive days. In Tulsa, this typically happens in late February or early March, but it varies year to year.
Here’s the timing mistake most Tulsa homeowners make: they wait until they see weeds popping up, and by then it’s too late for pre-emergent to work. You need to apply it before the seeds germinate.
At Complete Lawn Care, we monitor soil temperatures carefully and typically apply our first pre-emergent application in our 7-step program during the first week of March. Some years we’re out in late February if we have an early warm spell.
Products to Use:
- Prodiamine (Barricade): Lasts 3-6 months, excellent for crabgrass
- Dithiopyr (Dimension): Has some early post-emergent properties if you’re a bit late
- Pendimethalin (Pendulum): Budget-friendly option, lasts 2-4 months
Application Rate: Follow label instructions carefully. For prodiamine, typically 0.5-1.0 lb of active ingredient per acre. More isn’t better—over-application can damage your lawn.
Important Note for Bermuda Lawns: You can safely apply pre-emergent to dormant Bermuda grass in late February. The grass isn’t actively growing yet, so there’s no risk of damage.
Important Note for Fescue Lawns: Pre-emergent is safe on established fescue. However, if you plan to overseed your fescue in spring (not recommended in Tulsa—fall is better), skip the pre-emergent or you’ll prevent your grass seed from germinating too.
Fall Pre-Emergent Timing (For Winter Weeds)
When to Apply: Late August through mid-September
This application prevents winter weeds like henbit, chickweed, and poa annua from taking over your lawn during fall and winter. Apply when soil temperatures drop back down to around 70°F, which typically happens in early to mid-September in Tulsa.
This is the application most homeowners skip, and then they wonder why their lawn is full of purple henbit flowers in March. We include this critical fall application in Complete Lawn Care’s 7-step program because we see the dramatic difference it makes.
Products to Use:
- Prodiamine: Works well for winter weeds too
- Dithiopyr: Another solid choice
- Many combination products work for both seasons.
The Split Application Strategy
For the best control, many professionals (including Complete Lawn Care) use a split application approach:
- First application: Early March (full rate or slightly reduced)
- Second application: Late May or early June (half rate)
This maintains a barrier of protection throughout the entire growing season. The second application catches any gaps as the first application breaks down.
Post-Emergent Weed Control: Dealing With Active Weeds
Sometimes weeds slip through despite pre-emergent, or you’re starting mid-season and need to clean up existing weeds. That’s where post-emergent herbicides come in.
Timing for Post-Emergent Applications
Best Application Window: Apply when:
- Air temperatures are between 50 and 85°F.
- Weeds are actively growing (green and lush).
- No rain is expected for 24 hours.
- It’s not overly hot, or the lawn is stressed.
Avoid Applying When:
- Temperatures exceed 85-90°F (especially on Bermuda grass).
- Your lawn is drought-stressed.
- Within 2 weeks of seeding
- When frost is expected within 3 days
Spring Post-Emergent (March-May)
This is your window for controlling broadleaf weeds like dandelions, clover, and chickweed that emerged over winter or early spring.
Bermuda Grass: Wait until your Bermuda is fully greened up (typically late April) before applying post-emergent herbicides. Applying to dormant or partially dormant Bermuda can cause damage.
Fescue: You can apply post-emergent to fescue earlier in spring (March-April) since it’s actively growing during cool weather.
Products:
- Three-way herbicides (2,4-D, dicamba, MCPP): Excellent for most broadleaf weeds
- Specialty products for difficult weeds like spurge or oxalis
- Always use a product labeled safe for your grass type.
Summer Post-Emergent (June-August)
Summer weed control in Tulsa is tricky because of our heat. When temperatures climb into the 90s and stay there (which happens regularly), your lawn is stressed and more susceptible to herbicide damage.
The Temperature Rule: If the forecast high is above 85°F, either apply very early in the morning or wait for cooler weather. Above 90°F, avoid post-emergent applications entirely unless you’re using a product specifically formulated for high-temperature use.
Many homeowners make the mistake of seeing weeds in July and blasting them with herbicide on a 95°F day, only to damage their lawn more than the weeds. Patience is your friend here. Sometimes it’s better to tolerate a few weeds through the worst heat and address them in September.
Fall Post-Emergent (September-November)
Fall is actually an excellent time for weed control in Tulsa. Temperatures are moderate, and weeds are actively growing and more susceptible to herbicides.
For winter weeds that slipped past your pre-emergent, apply post-emergent in October or November while they’re small and actively growing. Don’t wait until spring when they’re mature and harder to kill.
Common Tulsa Weed Problems and Solutions
Crabgrass
Prevention is Everything: Pre-emergent in March is 95% effective. Once crabgrass is up and growing, it’s difficult and expensive to control.
If You Missed Pre-Emergent: Products containing quinclorac (Drive XLR8) or fenoxaprop can control young crabgrass in Bermuda. For fescue, options are more limited. Complete Lawn Care includes targeted crabgrass control in our summer applications when needed.
Dallisgrass
This is one of Tulsa’s most frustrating weeds. It’s a perennial that looks like a clump of thick grass and is extremely difficult to control.
Best Approach: Pre-emergent helps prevent new dallisgrass. For existing plants, repeated applications of MSMA (if you can find it—it’s restricted in some areas) or manual removal. Complete Lawn Care can assess your dallisgrass situation and recommend the best approach, which sometimes involves multiple treatments over several months.
Nutsedge (Nutgrass)
That bright green, fast-growing “grass” that pops up after rain? That’s nutsedge, and regular weed killers don’t touch it.
Solution: Specialty products containing sulfentrazone (Dismiss) or halosulfuron (SedgeHammer). Apply when nutsedge is actively growing. Multiple applications are usually needed because nutsedge reproduces through underground nutlets.
Henbit and Chickweed
These winter weeds are incredibly common in Tulsa lawns.
Best Control: Fall pre-emergent in September. If they’re already up, post-emergent applications in fall or early spring work well. Don’t wait until spring when they’re flowering—treat them in fall when they’re young.
Clover
Some people like clover in their lawn (it fixes nitrogen!), but if you want it gone:
Solution: Three-way broadleaf herbicides work well. Multiple applications may be needed. Interestingly, clover often indicates low nitrogen—a good fertilization program often naturally suppresses clover.
The Complete Lawn Care 7-Step Program Approach
At Complete Lawn Care, we’ve developed our 7-step program specifically for Tulsa’s climate and the weed challenges we face here. Here’s how we handle weed control throughout the year:
Step 1 (March): Pre-emergent application for summer weeds plus early spring fertilization
Step 2 (April): Post-emergent spot treatment for any winter weeds that survived, plus spring fertilization
Steps 3-5 (May-July): Fertilization with spot treatment for any breakthrough weeds, adjusted based on temperature
Step 6 (September): Fall pre-emergent for winter weeds plus fall fertilization
Step 7 (October-November): Late fall fertilization and any needed post-emergent for emerging winter weeds
This systematic approach, timed specifically to Tulsa’s weather patterns, provides consistent weed control while maintaining a healthy, thick lawn that naturally resists weed invasion.
Why a Healthy Lawn Is Your Best Weed Prevention
Here’s something most people don’t realize: the best weed control is a thick, healthy lawn. Weeds are opportunists—they fill in bare spots and thin areas.
This is why Complete Lawn Care’s approach isn’t just about spraying herbicides. We focus on:
- Proper fertilization: Strong, thick grass outcompetes weeds.
- Correct mowing height: Taller grass shades out weed seeds
- Adequate watering: Healthy grass recovers faster and fills in gaps.
- Soil health: We recommend annual soil testing to identify and correct any deficiencies.
We offer soil testing as a service because understanding your soil’s pH and nutrient levels is critical to growing a thick lawn that resists weeds naturally. We recommend homeowners have their soil tested once a year, particularly if you’re fighting persistent weed problems.
DIY vs. Professional Weed Control: What You Need to Know
You can absolutely handle weed control yourself if you’re willing to:
- Monitor soil temperatures and weather conditions closely.
- Purchase and properly apply multiple products at the right times
- Keep detailed records of what you applied and when.
- Adjust your approach based on results.
- Store pesticides safely and follow all label directions.
The challenge most busy Tulsa homeowners face isn’t ability—it’s consistency. Missing your pre-emergent window by two weeks can mean the difference between a weed-free lawn and fighting crabgrass all summer.
Professional programs like Complete Lawn Care’s 7-step approach take the guesswork and timing stress off your plate. We’re monitoring conditions, we’re automatically scheduled for the optimal application windows, and we’re adjusting our approach based on what we’re seeing across hundreds of Tulsa lawns.
Quick Reference: Tulsa Weed Control Calendar
For Both Bermuda and Fescue Lawns:
Month
Application Type
Target Weeds
Notes
February (late)
Pre-Emergent
Summer annual weeds, crabgrass
Apply when soil temp reaches 55°F.
March
Pre-Emergent
Summer annual weeds, crabgrass
Main application window
April
Post-Emergent
Winter broadleaf weeds
Spot treat as needed.
May
Post-Emergent
Spring/summer weeds
Watch temperatures.
June
Pre-Emergent (optional)
Late-germinating summer weeds
Split application strategy
July-August
Spot Treatment Only
Actively growing weeds
Avoid if temps are above 90°F.
September
Pre-Emergent
Winter annual weeds
Critical application for winter weed prevention
October-November
Post-Emergent
Emerged winter weeds
Treat young weeds while actively growing.
The Bottom Line on Weed Control Timing
The most important takeaway: timing matters more than the product you choose. The best herbicide applied at the wrong time won’t give you good results.
For most Tulsa homeowners, the two most critical applications are:
- Early March pre-emergent for summer weeds
- Early September pre-emergent for winter weeds
Get these two applications right, and you’ll prevent 80% of your weed problems.
Everything else—post-emergent spot treatments, second pre-emergent applications, and specialized treatments—builds on that foundation.
Ready for a Weed-Free Lawn This Year?
If you’re tired of fighting weeds or you’re not sure if you’re applying products at the right time, Complete Lawn Care’s 7-step program takes care of all the timing and guesswork for you. We’ve been perfecting our approach specifically for Tulsa lawns for years, and we know exactly when to apply what products for maximum effectiveness.
We’d be happy to assess your lawn’s current weed situation, discuss your specific challenges, and explain how our program addresses the particular weeds common in your neighborhood.
Contact Complete Lawn Care today to learn more about our 7-step lawn care program and finally get ahead of your weed problems this year. Let us handle the timing and applications while you enjoy a thick, green, weed-free lawn.
Visit us at www.completelawncaretulsa.com.
Remember: A healthy lawn is the best defense against weeds, and it all starts with the right treatment at the right time.