Dallisgrass clumps ruin the look of a manicured lawn, and its aggressive root system makes hand-pulling nearly useless. Without a targeted herbicide plan, this warm-season perennial simply returns thicker each year.
I’m Mohammad Maruf — the founder and writer behind Gardening Beyond. I spend my time comparing herbicide formulations, studying weed control trials, and analyzing aggregated owner reports to separate marketing claims from real-world results.
The right product stops dallisgrass at the root without torching your turf. This guide breaks down the best herbicide for dallisgrass based on efficacy data, application ease, and long-term lawn safety.
How To Choose The Best Herbicide For Dallisgrass
Not every weed killer is safe for your lawn. Dallisgrass requires a selective post-emergent approach — the wrong product can kill your turf, damage ornamentals, or simply fail to reach the root crown. Focus on three factors before buying.
Selective vs Non-Selective Chemistry
Non-selective herbicides kill every plant they touch. For dallisgrass growing inside a lawn, you need a selective formula that targets grass weeds while leaving desirable turf species unharmed. Look for active ingredients such as MSMA, quinclorac, mesotrione, or thiencarbazone-methyl — each works on dallisgrass when applied at the right growth stage.
Active Ingredient Efficacy
Different actives handle different weed sizes and lawn types. MSMA is a classic choice for dallisgrass in bermudagrass or zoysia, but it is restricted in some regions. Quinclorac works well on young plants and is safe on established warm-season turf. Mesotrione offers both pre- and post-emergent control on cool-season grasses. Crossbow (triclopyr + 2,4-D) targets broadleaf weeds and some grassy weeds in non-turf areas or pasture. Match the active to your grass type and local regulations.
Application Timing and Method
Dallisgrass is easiest to kill in late spring or early summer when it is actively growing and before seed heads form. Most concentrates require surfactant or non-ionic wetting agent to improve leaf adhesion. Watering-in guidelines vary by product — some need rain within days, others require a dry period. Always read the label for tank-mix instructions and grazing restrictions if you have pets or livestock.
Quick Comparison
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| Model | Category | Best For | Key Spec | Amazon |
|---|---|---|---|---|
| Southern Ag Crossbow | Broadleaf & Brush | Large areas & woody weeds | 128 oz per gallon | Amazon |
| Liquid Harvest Mesotrione | Pre/Post Emergent | Cool-season turf | 32 oz concentrate | Amazon |
| Bayer Celsius WG | Selective Granule | Hard-to-control weeds | 10 oz granules | Amazon |
| Select Source Quinclorac 75 | Selective Powder | Young dallisgrass & crabgrass | 1 lb powder | Amazon |
| Target 6 Plus MSMA | Professional Liquid | Warm-season turf & sod farms | 2.5 gallon jug | Amazon |
| Quali-Pro MSM Turf | Turf Selective | Ornamental turf & fairways | 8 oz liquid | Amazon |
| Hi-Yield Grass Killer | Postemergence | Gardens & ornamentals | 8 oz concentrate | Amazon |
In-Depth Reviews
1. Southern Ag Crossbow Specialty Herbicide
Southern Ag Crossbow combines triclopyr and 2,4-D in a low-volatile formulation designed to tackle woody brush, broadleaf weeds, and tough perennial grasses in non-turf areas, pastures, and fence lines. The gallon jug makes up to 96 gallons of spray solution, offering exceptional coverage for large properties where dallisgrass has spread beyond the lawn border.
The active ingredients work systemically, traveling to the root crown to prevent regrowth. Users report visible wilting within 7 to 14 days on established dallisgrass clumps. Because it is non-selective toward desirable turf grasses, it is best reserved for spot treatment in areas where lawn grass is absent or for prepping a field before reseeding.
Crossbow requires a surfactant for optimal leaf wetting, and application during active growth in late spring yields the most consistent results. The low-volatile formula reduces drift risk, making it a safer choice around gardens and shrubs when used carefully.
What works
- Excellent value per gallon of concentrate
- Low drift formulation for safer spot treatment
- Systemic action reaches deep roots
What doesn’t
- Non-selective to desirable turf grasses
- Requires surfactant for best results
2. Liquid Harvest Mesotrione 32oz
Liquid Harvest Mesotrione delivers the same active ingredient found in the popular Tenacity brand at a more accessible price point. It works both pre-emergently to stop dallisgrass seedlings and post-emergently to control existing weeds, making it one of the most versatile options for cool-season turfgrasses like tall fescue, Kentucky bluegrass, and perennial ryegrass.
The product inhibits photosynthesis in susceptible plants, distributing through both roots and leaves for complete kill. Users note that visible whitening of treated weeds appears within 10 to 14 days, with full death following in 2 to 3 weeks. Activation requires water — if no rain falls within 10 days, irrigation of about 0.15 inches is needed to trigger the chemical reaction.
This concentrate covers 46 broadleaf weed and grass species, including crabgrass, clover, and dallisgrass. It is safe on centipede grass, buffalo grass, and St. Augustine grass (sod only), but should be avoided on bentgrass, zoysiagrass, and bermudagrass unless applied during dormancy.
What works
- Dual pre- and post-emergent action
- Safe on many cool-season turf varieties
- Large spectrum of target weeds
What doesn’t
- Rain or irrigation required within 10 days
- Not labeled for all warm-season turf types
3. Bayer Celsius WG 10 oz
Bayer Celsius WG combines thiencarbazone-methyl, iodosulfuron-methyl-sodium, and dicamba in a wettable granule formulation that delivers exceptional control over hard-to-kill weeds including dallisgrass suppression, dollarweed, Virginia buttonweed, and Florida pusley. The triple-active chemistry reduces the chance of resistance development and works across a wide temperature window without the heat stress limitations found in many other herbicides.
This product is designed for warm-season turf professionals managing golf courses, sports fields, and commercial landscapes. The granular format dissolves easily in water and requires no additional surfactant in most cases, simplifying tank preparation. Users report seeing results on dallisgrass within 10 to 14 days, with suppression improving after a second application timed 4 to 6 weeks later.
Celsius WG is safe on bermudagrass, zoysiagrass, St. Augustinegrass, and centipedegrass when used according to label rates. The convenient application window without high-temperature restrictions makes it a go-to choice for southern lawns where summer heat often limits other herbicides.
What works
- Triple active ingredients resist weed resistance
- No high-temperature application restrictions
- Safe on major warm-season turf types
What doesn’t
- Premium price point for small lawns
- Dallisgrass suppression requires repeat treatment
4. Select Source Quinclorac 75 Herbicide
Select Source Quinclorac 75 is a dry flowable formulation containing 75 percent quinclorac, a selective herbicide that targets grassy weeds such as dallisgrass, crabgrass, and foxtail without harming established bermudagrass or zoysiagrass. The 1-pound container mixes at a maximum rate of 0.367 ounce per gallon of water — roughly 1.4 teaspoons per gallon — making it highly economical for ongoing spot treatment.
Quinclorac works by disrupting cell wall synthesis in susceptible grasses, causing growth to stop within days and full necrosis within 2 to 3 weeks. It is most effective on young, actively growing dallisgrass plants before they develop extensive root rhizomes. Users on athletic fields and commercial properties consistently report clean-up of crabgrass and dallisgrass after two applications spaced 3 to 4 weeks apart.
This product is labeled for use on residential lawns, schools, parks, and landscape beds. It requires a non-ionic surfactant for optimal leaf coverage and should not be applied to St. Augustinegrass or centipedegrass due to risk of injury.
What works
- Highly concentrated — goes a long way
- Selective on bermudagrass and zoysia
- Proven on crabgrass and dallisgrass
What doesn’t
- Not safe on St. Augustine or centipede turf
- Requires surfactant for best adhesion
5. Target 6 Plus MSMA Turf Herbicide
Target 6 Plus MSMA contains 48.2 percent monosodium acid methanearsonate, the industry-standard active for controlling dallisgrass, crabgrass, johnsongrass, and nutsedge in warm-season turf. This 2.5-gallon jug is a professional-grade solution used by golf courses, sod farms, and highway maintenance crews where heavy weed pressure demands a reliable knockdown.
MSMA works by interfering with phosphorus uptake in target weeds, causing stunting and death over 10 to 21 days. The standard mix rate is 2 ounces per gallon of water for general applications, with specific rates for particular weeds noted on the label. Users report that dallisgrass clumps turn yellow within a week and die completely after a second treatment when applied during active summer growth.
This product is restricted in some states and requires an applicator license in certain regions. It is safe on bermudagrass, zoysiagrass, and centipedegrass but can cause injury to St. Augustinegrass and cool-season turf varieties. Always verify local regulations before purchase.
What works
- Industry standard for dallisgrass control
- Large 2.5-gallon volume for heavy use
- Fast visible results on warm-season turf
What doesn’t
- Restricted in several states
- May require applicator license
6. Quali-Pro MSM Turf Herbicide 8oz
Quali-Pro MSM Turf Herbicide is a selective post-emergent formulation designed for ornamental turf including residential lawns, parks, cemeteries, and golf course fairways. The 8-ounce bottle targets both broadleaf and grassy weeds while maintaining safety on established turf species when used at labeled rates.
The active ingredient in MSM Turf works systemically, moving through the plant to the roots for complete control. Users report good results on dallisgrass when applied early in the season before plants reach full maturity. The shelf life extends up to 3 years when stored in a dry, temperature-controlled environment away from fertilizers and seeds.
This product is best suited for smaller lawns or spot treatments due to its 8-ounce volume. It requires a non-ionic surfactant and should be applied during calm weather to prevent drift onto ornamentals and flower beds.
What works
- Selective on ornamental turf grasses
- Long shelf life with proper storage
- Good for spot treatment on small lawns
What doesn’t
- Small bottle limits coverage area
- Requires surfactant for optimal results
7. Hi-Yield Grass Killer Postemergence Herbicide
Hi-Yield Grass Killer is a selective post-emergent herbicide formulated to stop grassy weed growth without harming vegetables, flowers, trees, and shrubs. The 8-ounce concentrate makes up to 8 gallons of spray solution, providing an budget-friendly entry point for homeowners who need to manage dallisgrass in garden beds and around ornamentals.
The product works quickly — users report visible cessation of growth within 2 days of application, with full die-off occurring over the following 1 to 2 weeks. It is most effective on young, actively growing weeds and should be applied when temperatures are between 60 and 85 degrees Fahrenheit for best translocation.
Because Hi-Yield is labeled for use around edible plants and ornamentals, it offers flexibility that many professional-grade herbicides lack. However, it is not designed for broadcast lawn applications and works best as a spot treatment for isolated dallisgrass clumps in mixed planting areas.
What works
- Safe around vegetables and ornamentals
- Fast-acting — visible results in 2 days
- Affordable entry-level option
What doesn’t
- Not for broadcast lawn application
- Small 8-ounce bottle for limited coverage
Hardware & Specs Guide
Active Ingredients
The active ingredient determines which weeds are controlled and how safe the product is on your lawn. MSMA is the historical standard for dallisgrass in warm-season turf, but it is restricted in some states. Quinclorac, mesotrione, and thiencarbazone-methyl offer selective post-emergent control with fewer regulatory barriers. Triclopyr + 2,4-D (Crossbow) works well in non-turf areas where drift risk is low. Always match the active to your grass type and local laws.
Concentrate vs Ready-to-Use
Concentrates require mixing with water and often a surfactant but provide far more coverage per dollar. An 8-ounce concentrate can make 8 to 96 gallons of spray solution depending on the product. Ready-to-use formulas cost more per application and are best for small spot treatments. For large lawns or recurring dallisgrass problems, a concentrate is the smarter investment.
Surfactant Compatibility
Most selective herbicides require a non-ionic surfactant to break surface tension on waxy weed leaves. Without it, the chemical beads up and rolls off, drastically reducing efficacy. Some products like Bayer Celsius WG include built-in wetting agents, but many others require a separate purchase. Budget for surfactant when calculating total application cost.
Turf Tolerance
Not all herbicides are safe on all grass types. MSMA and quinclorac work on bermudagrass and zoysia but can injure St. Augustine and centipede. Mesotrione is safe on cool-season grasses like fescue and bluegrass but can damage bermudagrass. Celsius WG is one of the few products with a wide safety margin across warm-season varieties. Check the label against your lawn species before mixing.
FAQ
What is the best time of year to apply herbicide for dallisgrass?
Can I use a non-selective herbicide on dallisgrass in my lawn?
How long does it take for dallisgrass to die after herbicide application?
Final Thoughts: The Verdict
For most homeowners targeting dallisgrass in warm-season lawns, the best herbicide for dallisgrass winner is the Bayer Celsius WG because it combines three active ingredients for resistance management, works across a wide temperature range, and is safe on multiple turf types. If you need a budget-friendly concentrate for spot treatment around ornamentals, grab the Hi-Yield Grass Killer. And for large-scale pasture or fence-line dallisgrass infestations, nothing beats the coverage and systemic action of Southern Ag Crossbow.