Having Dallisgrass weed on your yard or lawn can be a major headache due to its ability to spread quickly and kill your grass. The warm-season perennial weed is a pesky problem as it affects all kinds of lawns, including Zoysia, Bermuda, and St. Augustine.
When facing an aggressive and hard-to-kill weed, you’d surely want to know, ‘what is the best dallisgrass killer?’
How to Identify and Control Dallisgrass
Dallisgrass in your lawn or turf is easy to identify. The weed appears as a significant clump that grows several inches high, with thin blades that assume a spiraling growth habit. Its roots are tough to pull out as it’s fibrous and tends to dig down deep into the soil. Dallisgrass looks like wheat and is an invasive weed.
Early detection is paramount to killing dallisgrass weed effectively. While it’s possible to use pre-emergent herbicides as a way to prevent the weed from appearing in the first place, dallisgrass will usually appear in the warmer months whether you like it or not.
What’s worse is that dallisgrass tends to come back year after year, starting out in bare patches and then establishing itself as the dominant grass in your yard or lawn.
What Can You Use to Kill Dallisgrass?
MSMA or CMA
MSMA or monosodium methanearsonate is a broad-spectrum herbicide that’s often used to control broadleaf weeds and grasses. It’s worth noting that MSMA is an organic arsenical pesticide, and is thus very effective against dallisgrass, as well as crabgrass (its close cousin), chickweed, pigweed, and johnsongrass, among others.
This herbicide is best used as a post-emergent and when you’re looking to remove established dallisgrass weed in your yard or garden. It’s also selective, so it tends to not hurt your grass as long as you follow the manufacturer’s instructions for mixing and application.
Glyphosate
Glyphosate is a popular active ingredient in herbicides such as RoundUp and is particularly effective versus a dallisgrass infestation. However, it’s worth noting that the product is a non-selective and systemic herbicide, which means that glyphosate has the ability to kill all the plants it comes across.
When using glyphosate, you’ll have to be aware that your turf can be affected. It’s similar to hitting the reset button if you wish to completely eradicate dallisgrass in your lawn. However, a single application may not be enough, and you might need to spray a second time or follow up with a pre-emergent herbicide.
Dithiopyr
Speaking of pre-emergents, dithiopyr is a good prevention herbicide that works on dallisgrass seeds and crabgrass seeds. Dithiopyr can control pesky weeds such as oxalis, annual bluegrass, crabgrass, chickweed, and bittercress, among others.
The best time to spray pre-emergent for dallisgrass is in late winter or early spring, or right when the seed germinates. In addition, it’s recommended that you irrigate your lawn well so the water and chemical seeps into the soil and reaches the seeds. For every herbicide you use, you should follow the instructions as stated on the label.
Bensulide
Bensulide is another popular pre-emergent spray that can be used to control broadleaf weeds and annual grasses. It’s safe to use on vegetables and can quickly kill persistent dallisgrass seeds left over on your lawn.
The broadleaf herbicide is selective and should be sprayed on the ground before the seed germination phase occurs. Otherwise, it won’t be as effective, and some of the dallisgrass seeds will emerge and multiply. If you’ve somehow missed the pre-emergent window and now see tufts of the weed in your yard, then it’s recommended that you switch to a post-emergent herbicide such as MSMA or glyphosate.
Oryzalin
Some of the anti-dallisgrass products you’ll encounter contain the active ingredient Oryzalin. This chemical is effective in soybean farms and when protecting fruiting trees against invasive weeds, as well as stopping dallisgrass from growing on your turf.
The pre-emergent herbicide is sold in various forms, including liquid concentrate, granule, powder, and emulsifier concentrate. Oryzalin’s mechanism of action is via plant microtubule disruption and inhibiting the growth of weeds as they enter the germination phase.
Oryzalin works on both cool and warm-season types of grass and controls dallisweed, foxtail, barnyardgrass, and purslane, among others. Annual spraying or application is recommended to prevent dallisgrass weed from showing up on your lawn.
DCPA
DCPA or dimethyl tetrachloro terephthalate is known in the commercial industry as Dacthal. The organic compound serves as a pre-emergence herbicide that can control annual weeds in several crop and lawn settings. Like other herbicides, DCPA can kill broadleaf weeds and annual grasses in vegetable gardens, ornamental landscapes, and lawns.
You may not be able to see DCPA and Bensulide ingredients in most herbicides, as they are largely kept reserved for professional use.
However, if you have permission or have contacted a professional to apply the herbicide then you’ll find the results in killing dallisgrass more than satisfactory. Also, you may need to spray a post-emergent herbicide as the months get warmer.