Dallisgrass is one of the toughest weeds to eliminate from a warm-season lawn. Its thick, clumping growth habit and deep root system resist standard lawn treatments, often spreading faster than you can dig it out. Without a selective chemistry that targets the weed without burning the surrounding turf, you are stuck in a cycle of hand-pulling and frustration.
I’m Mohammad Maruf — the founder and writer behind Gardening Beyond. I spend my time comparing herbicide active ingredients, studying turfgrass tolerance charts, and analyzing thousands of verified owner reports to find the formulations that deliver real, lasting results for specific lawn weed problems.
This guide breaks down the chemistry and application strategy behind five proven products that handle the job. Finding the right best dallisgrass weed killer means matching the active ingredient to your grass type and the stage of the infestation.
How To Choose The Best Dallisgrass Weed Killer
Selecting the right product requires understanding that Dallisgrass has a different physiology than crabgrass or dandelion. Its rhizomes and deep crown require a chemistry that translocates through the entire plant system. The wrong choice can leave the root intact while only singeing the leaves, allowing the weed to rebound within weeks.
The Active Ingredient Decides Everything
MSMA (Monosodium Methanearsonate) is the historical gold standard for Dallisgrass control in warm-season lawns like Bermuda and Zoysia. It is highly selective and translocates to the root system, but requires precise mixing to avoid turf scorching. Mesotrione (the active in Tenacity generics) works on cool-season grasses and offers pre- and post-emergent activity, though it may need multiple applications for mature Dallisgrass clumps.
Turfgrass Tolerance Is Non-Negotiable
Applying a product that is safe for St. Augustine on a Bermuda lawn can waste money and time, while using MSMA on a Fescue lawn can kill the entire turf. Always cross-check the label against your specific grass species before mixing. Cool-season grasses like Kentucky Bluegrass and Tall Fescue tolerate mesotrione well, while warm-season grasses like Bermuda and Zoysia tolerate MSMA best.
Application Timing and Method
Post-emergent herbicides work best when Dallisgrass is actively growing in late spring through early fall. A spray dye indicator helps track coverage and prevents overlapping, which can cause localized turf browning. For large infestations, a tank sprayer with constant agitation delivers more consistent results than a hose-end sprayer.
Quick Comparison
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| Model | Category | Best For | Key Spec | Amazon |
|---|---|---|---|---|
| Target 6 Plus (MSMA 48.2%) | Premium Selective | Warm-season turf with heavy Dallisgrass | MSMA 48.3% concentration | Amazon |
| Liquid Harvest Mesotrione | Premium Broad-Spectrum | Cool-season lawns and pre-emergent control | Mesotrione 8 oz concentrate | Amazon |
| Ortho WeedClear Lawn Weed Killer | Mid-Range RTU | Quick spot treatment for small patches | Battery-powered Comfort Wand | Amazon |
| BioAdvanced Weed Killer for Lawns | Mid-Range Concentrate | Large lawn coverage against broadleaf weeds | Covers up to 16,000 sq ft | Amazon |
| Spectracide Weed and Grass Killer | Budget Non-Selective | Driveways, patios, and gravel areas | Diquat Dibromide active | Amazon |
In‑Depth Reviews
1. Target 6 Plus (MSMA 48.2%) Turf Herbicide
This is the benchmark product for Dallisgrass that owners of Bermuda and Zoysia lawns turn to when nothing else works. The 48.3% MSMA concentration is the same formulation used by golf course superintendents, and it translocates through the entire Dallisgrass plant, killing the crown and rhizomes that cause regrowth. Multiple verified reports confirm it knocks out heavy infestations on Japanese Zoysia within weeks.
Mixing precision is critical here. At the label rate of 2 oz per gallon of water, it kills Dallisgrass selectively, but overdosing by even 25% can stress Bermuda into temporary dormancy. Owners who follow the supplemental data sheets and use a 2-gallon battery-powered sprayer with a dye indicator get the best results with no turf damage.
A single 2.5-gallon jug lasts multiple seasons for most homeowners, making it a cost-effective solution despite the upfront investment. It works faster in warmer temperatures, with visible wilting often seen within 48 hours. This is not a product for cool-season lawns, but for warm-season turf it is unmatched.
What works
- Selectively kills Dallisgrass at the root without harming Bermuda or Zoysia when mixed correctly
- Very concentrated; a single purchase lasts years for spot treatment
- Visible results in 2-3 days during active growing season
What doesn’t
- Requires careful measurement; overdosing can stress or temporarily brown Bermuda turf
- Not labeled for use on cool-season grasses like Fescue or Kentucky Bluegrass
- Larger container size may be intimidating for homeowners with small patches
2. Liquid Harvest Mesotrione – 8oz Concentrate
This mesotrione concentrate is the go-to option for cool-season lawn owners who need both pre-emergent prevention and post-emergent control. It targets 46 broadleaf and grassy weeds including Dallisgrass, crabgrass, and clover, while being safe on Kentucky Bluegrass, Tall Fescue, and Perennial Ryegrass. It works by inhibiting photosynthesis in susceptible plants, which means full death can take 2-3 weeks.
Activation requires watering within 10 days if no rain falls, which is a specific requirement that new users sometimes miss. Owners who pair it with a spray dye indicator in a 2-gallon tank sprayer report the most consistent results, especially when targeting established Dallisgrass clumps that need a higher dose rate. Multiple reports note that it kills weeds that other products cannot touch.
The 8 oz bottle treats a significant area, making it a value-driven choice for those who already own a sprayer. One caveat: it can temporarily whiten St. Augustine grass if over-applied, so accurate mixing is essential. For Northern lawns with mixed Fescue and Bluegrass, this is a top-tier systemic solution.
What works
- Safe on most cool-season turfgrasses including Fescue, Bluegrass, and Ryegrass
- Offers pre-emergent activity that prevents new Dallisgrass seeds from germinating
- Very versatile; controls 46 different weed species in one application
What doesn’t
- Requires soil activation via rainfall or irrigation within 10 days
- Takes 2-3 weeks to fully kill mature Dallisgrass clumps
- Can whiten or damage St. Augustine grass if mixing ratio is off
3. Ortho WeedClear Lawn Weed Killer Ready-To-Use with Comfort Wand
For homeowners who want a zero-mix, grab-and-go solution for small Dallisgrass patches in a mixed lawn, this ready-to-use formula with the battery-powered Comfort Wand eliminates the need for tank sprayers. It is labeled for use on Fescues, Kentucky Bluegrass, Ryegrass, Bermudagrass, and Zoysiagrass, which covers most common lawn types. The wand makes spot-treating individual clumps intuitive.
This product works best on young, actively growing weeds in spring or fall within the 45°F to 90°F window. Owners consistently report that it kills dandelion and clover quickly, but tougher weeds like Dallisgrass may require a second application after a couple of weeks. The formula is slower-acting than MSMA-based products, taking up to a month for full results.
The battery-powered wand is the standout feature here, providing accurate coverage without bending over or hand-pumping. However, for large or mature Dallisgrass infestations, the concentrate-based products in this guide are more effective. This is a maintenance tool for keeping a clean lawn, not a heavy-duty eradication weapon.
What works
- Battery-powered wand makes spot treatment effortless and precise
- Safe for a wide range of lawn grasses including Bermuda and Zoysia
- No mixing or measuring required
What doesn’t
- Slow-acting; may need 2-3 applications for mature Dallisgrass
- 1.33 gal container is expensive per treatment compared to concentrates
- Less effective against deep-rooted, well-established Dallisgrass clumps
4. BioAdvanced Weed Killer for Lawns Concentrate, 32oz
This concentrate offers tremendous coverage at a competitive price point, treating up to 16,000 square feet per bottle. The three-way active ingredient blend of Dicamba, Mecoprop-P, and dimethylamine salt targets over 200 broadleaf weeds including clover, dandelion, and dollar weed. For general lawn maintenance where Dallisgrass is present alongside broadleaf invaders, this is a strong all-in-one option.
Owner reports highlight its effectiveness on dollar weed and dandelion, with best results when followed by a 13-13-13 fertilizer application to help the turf recover. It is labeled for both Southern and Northern lawns, giving it wider versatility than MSMA-only products. Some users noted that it reduced nutgrass but did not eliminate it entirely, and it caused temporary browning in Bermuda that resolved as the grass grew out.
The sprayability and value are the main draws here. A single bottle does an entire front and back lawn, and the formula is cost-effective enough for regular seasonal treatments. However, for a heavy, isolated Dallisgrass clump, a more targeted product like MSMA or mesotrione will deliver faster knockdown.
What works
- Excellent coverage value; treats up to 16,000 sq ft per bottle
- Kills over 200 broadleaf weed types with one application
- Suitable for both warm-season and cool-season lawns
What doesn’t
- Less selective for grassy weeds like Dallisgrass; may need repeat applications
- Can cause temporary Bermuda turf browning if applied during heat stress
- Sprayer nozzle can be difficult to twist into the on position
5. Spectracide Weed and Grass Killer Concentrate, 32oz
This non-selective concentrate with Diquat Dibromide is the right choice for Dallisgrass growing in driveways, patios, fence lines, and gravel areas where you do not care about sparing the surrounding vegetation. It kills visible growth within 3 hours, which is significantly faster than systemic herbicides. The Accumeasure cap makes mixing straightforward, though some owners bypass it entirely for the old-style cap.
Because it is non-selective, this product will kill any grass it touches, so it has no place in a manicured lawn. For eliminating Dallisgrass clumps that have spread into cracks in concrete or along fence lines, it is hard to beat. It is rainfast in just 15 minutes, which means you can spray and not worry about weather.
The 32 oz concentrate covers about 1,350 square feet when mixed according to directions, making it economical for hardscape areas. Owners note that results are visible within three days even without a heavy dose. Keep this product for spot-treating weeds in non-turf areas where a fast, non-selective kill is the priority.
What works
- Visible results in as fast as 3 hours on Dallisgrass foliage
- Rainfast within 15 minutes, allowing flexible application timing
- Accumeasure cap simplifies mixing for non-chemical users
What doesn’t
- Non-selective; kills any turfgrass it contacts, unsuitable for lawn use
- Does not translocate deep; established Dallisgrass roots may resprout
- Small coverage area per bottle compared to other concentrates
Hardware & Specs Guide
Active Ingredients and Selectivity
MSMA is the most selective and effective post-emergent option for Dallisgrass in warm-season turf, translocating through the plant to kill the root system. Mesotrione offers dual pre- and post-emergent activity for cool-season lawns, targeting the weed at the seedling and mature stages through photosynthesis inhibition. Dicamba-based blends provide broad-spectrum broadleaf control but are less reliable on mature grassy weeds like Dallisgrass. Diquat Dibromide delivers rapid non-selective foliage burn-off for hardscape areas.
Coverage and Mixing Ratios
Concentrates like MSMA and mesotrione require a tank sprayer and precise mixing, with typical rates of 2 oz per gallon of water for MSMA. Ready-to-use products like the Ortho WeedClear offer convenience for small patches but cost more per treated square foot. Coverage varies widely: the 32 oz BioAdvanced concentrate treats up to 16,000 square feet, while the 32 oz Spectracide concentrate covers only 1,350 square feet due to its higher required dilution rate for non-selective knockdown.
FAQ
Can I use MSMA on my Fescue lawn to kill Dallisgrass?
How long does it take for mesotrione to kill Dallisgrass?
Why does my Dallisgrass come back after using a broadleaf weed killer?
Final Thoughts: The Verdict
For most gardeners with a warm-season lawn, the best dallisgrass weed killer winner is the Target 6 Plus (MSMA 48.2%) because it delivers selective, deep-rooted eradication that no other chemistry matches on Bermuda and Zoysia turf. If you manage a cool-season lawn and need pre-emergent prevention alongside post-emergent control, grab the Liquid Harvest Mesotrione. And for a quick, no-mix solution for small, visible Dallisgrass patches in a mixed lawn, nothing beats the convenience of the Ortho WeedClear with Comfort Wand.