MSMA for Dallisgrass and Crabgrass in Texas: Is It Still Legal

If you’ve been battling dallisgrass or crabgrass in your North Texas lawn, you’ve probably come across MSMA. For decades it was the gold-standard herbicide for grassy weeds in Bermudagrass turf across the South. Then it seemed to disappear from store shelves, and now homeowners are left wondering: is MSMA still legal in Texas, and if so, who can actually use it? The answer is complicated — and understanding it matters before you make any decisions about your weed control services approach this season.

What Is MSMA?

MSMA stands for monosodium methanearsonate. It’s an organoarsenic herbicide, meaning its active ingredient contains arsenic bonded to an organic compound. For decades it was among the most effective selective herbicides available for controlling grassy weeds in warm-season turf — particularly in Bermudagrass lawns where it could knock out weeds without significant damage to the desirable grass beneath.

MSMA worked by interfering with the weed’s metabolic processes, causing chlorosis and ultimately killing the plant through a combination of contact and systemic activity. It was especially prized in Texas because almost nothing else could reliably control mature dallisgrass in established Bermudagrass turf without killing the lawn along with the weed.

Why The EPA Pulled It From Residential Use

The trouble with MSMA, from a regulatory standpoint, is the arsenic. While the arsenic in MSMA is organically bound and behaves differently from inorganic arsenic, the EPA’s re-evaluation process raised concerns about arsenic accumulation in soil and potential leaching into groundwater under certain conditions.

Between 2009 and 2013, the EPA cancelled MSMA registrations for most residential and general turf uses as part of a negotiated voluntary cancellation process with manufacturers. The key outcomes were:

• Residential lawn use: Cancelled. Homeowners can no longer legally purchase or apply MSMA on their own residential turf.
• General landscape contractor use on residential turf: Also cancelled for standard lawn care applications on home lawns.
• Retained uses: MSMA remained legal for use on golf courses, highway rights-of-way, and by licensed pesticide applicators on sod farms under specific label conditions.

This is why you stopped seeing MSMA at Home Depot and Lowe’s. It wasn’t banned outright in every context — it was removed from the consumer market and restricted to specific professional and commercial applications.

Current Legal Status In Texas

As of 2025, MSMA is not legal for homeowner use on residential turf in Texas. Period. If someone is selling you an unlabeled product they claim is MSMA for your home lawn, that is a red flag — applying a pesticide in a manner inconsistent with its label is a federal violation under FIFRA (the Federal Insecticide, Fungicide, and Rodenticide Act).

Where MSMA does remain legal in Texas:

• Golf courses — licensed applicators managing golf turf can use MSMA under current label restrictions.
• Highway rights-of-way — state and contractor applications for roadside vegetation management.
• Sod farms — licensed applicators producing sod commercially may use MSMA under specific label provisions.

Texas A&M AgriLife Extension confirms that residential turf applications of MSMA are not an approved use, and any licensed lawn care company operating legally will not be applying MSMA to your home lawn regardless of how effective it once was.

Why Dallisgrass Is So Difficult Without MSMA

Dallisgrass (Paspalum dilatatum) is a perennial grassy weed that comes back from its root system year after year. Unlike crabgrass, which is an annual and dies off each winter, dallisgrass establishes deep, persistent rhizomes in the soil. It germinates in late spring, grows in clumps with a distinctive circular or star-shaped growth pattern, and its seed heads appear on tall, spreading stalks through summer and fall.

The perennial nature is what makes it so hard to kill. You can’t simply prevent it with pre-emergent herbicides the way you can with crabgrass, because it’s regrowing from existing root tissue underground. Most post-emergent herbicides that are safe on Bermudagrass don’t touch it effectively. MSMA, applied in two or three repeat applications spaced about two weeks apart, was the most reliable tool for weakening and eventually killing established dallisgrass clumps — which is exactly why its removal from the residential market was so disruptive.

Dallisgrass vs. Crabgrass: Know What You’re Fighting

Before reaching for any product, you need to correctly identify which weed you’re dealing with. They require different strategies:

• Dallisgrass: Perennial. Grows in circular clumps. Wide, flat leaf blades with a prominent midrib. Produces seed heads on long, jointed stems. Returns from roots each year. Very difficult to control post-emergence.
• Crabgrass: Annual. Dies in winter, returns from seed each spring. Lower-growing and more sprawling. Lighter green than most turf. More effectively managed with pre-emergent herbicides applied in late winter or early spring before soil temperatures hit 55°F at a 4-inch depth.

Many homeowners confuse the two because both are coarse, off-color grassy weeds that disrupt the uniform look of a Bermudagrass lawn. But the right timing and chemistry for each is different, which is why a proper diagnosis matters before any treatment is applied.

What Alternatives Exist Now For Grassy Weed Control

Texas A&M and weed scientists across the South have spent years evaluating MSMA alternatives. No single product matches MSMA’s effectiveness on dallisgrass, but multi-application programs using newer chemistry can make meaningful progress:

• Sethoxydim (Segment II, Vantage): A post-emergent grass killer that works well on certain grassy weeds in non-Bermudagrass lawns. Limited use in Bermudagrass due to injury risk — but useful in zoysiagrass or centipede contexts.
• Drive XLR8 (quinclorac): Effective on crabgrass and some other annual grassy weeds. Works better on young, actively growing plants. Less effective on mature dallisgrass.
• Fahrenheit (metsulfuron + dicamba): Provides suppression of some grassy weeds along with broadleaf control. Can cause temporary injury to Bermudagrass if applied during stress periods.
• Multi-application suppression programs: For dallisgrass specifically, repeated applications of available chemistry throughout the growing season can suppress regrowth and weaken the plant over one to two seasons, even if complete eradication is not guaranteed in a single year.
• Pre-emergent programs for crabgrass: Prodiamine, pendimethalin, or dithiopyr applied at the right window — late February to mid-March in the Arlington and DFW area — can significantly reduce crabgrass pressure before it ever germinates.

Understanding how synthetic auxin herbicides kill broadleaf weeds without harming grass also helps clarify why different chemistry is needed for grassy weeds like dallisgrass and crabgrass — grass-selective herbicides work through completely different modes of action than broadleaf chemistry does.

Why A Licensed Professional Is Essential

Beyond the legal question of who can apply what, grassy weed control in Bermudagrass requires careful timing and product selection to avoid injuring the desirable turf. Applying the wrong product, at the wrong rate, during heat stress or drought, or on a lawn that hasn’t fully established can result in significant turf damage on top of inadequate weed control. A licensed pesticide applicator knows how to read current label requirements, identify the specific weed accurately, time applications for maximum effectiveness with minimum turf risk, and set realistic expectations when no single product delivers a silver-bullet solution.

Texas A&M AgriLife Extension recommends consulting a licensed lawn care professional when dealing with persistent grassy weeds like dallisgrass, precisely because the post-MSMA landscape requires a more strategic, multi-visit approach than most homeowners can execute effectively on their own.

What Hamann Does For Grassy Weed Pressure In North Texas

At Hamann Lawn Care & Weed Control, we’ve adapted our grassy weed programs for the post-MSMA era. We start with accurate identification — because the right product at the right time depends entirely on what weed you’re actually dealing with. From there, we build a treatment plan that targets the weed’s growth stage, respects your specific grass type, and works within the realistic expectations of what current chemistry can deliver. For dallisgrass, that often means a multi-season suppression strategy paired with a healthy, dense turf program that gives your Bermudagrass the competitive edge it needs to crowd weeds out over time.

We serve Arlington, Mansfield, Burleson, Grand Prairie, and surrounding areas of Tarrant and Johnson County.