Our readers keep the lights on and my morning glass full of iced black tea. As an Amazon Associate, I earn from qualifying purchases.7 Best Herbicide For Johnson Grass | Don’t Let It Take Over

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Eraser contains a full 41% glyphosate, identical to the active ingredient in the consumer-grade Roundup but at a fraction of the per-ounce cost. The low-odor, water-based formula mixes readily with no foaming and is rainfast within hours — critical when you are racing a summer storm forecast. Users consistently report complete browning within 7-14 days on tough perennials, with rhizome death requiring the full two-week window provided the plant was actively growing at application.

Seventeen-year repeat buyers confirm the formula has remained consistent over nearly two decades, which is unusual in a market where manufacturers quietly change surfactants. At 8 oz per gallon for standard weed pressure, a single quart treats roughly 4 gallons of spray solution, giving you enough coverage for a substantial fence line or field edge infested with Johnson grass. The product has no residual soil activity, so you can replant or reseed once the visible vegetation is dead.

Where Eraser falls short is its complete non-selectivity — it kills everything green, including desirable turf, ornamentals, and forage. If you need to remove Johnson grass from the middle of a flower bed or a clover food plot, this is not your tool. Additionally, some users noted that heavy, mature stands of poison ivy required a second spot application, so very old Johnson grass with massive rhizome reserves may need a follow-up treatment at the same concentration.

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Ferti-lome positions this as a selective grass killer that you can spray over vegetables, gardens, trees, shrubs, and ornamentals without damaging them — making it a rare tool for Johnson grass emerging in a mixed planting bed. The concentrate makes up to 8 gallons of spray solution, and the label claims growth cessation within 2 days of application. Real-world owner tests confirm it works on Bermuda and quackgrass, though the effect is genuinely slow, requiring 1-3 weeks for complete kill.

The active ingredient targets grass-specific enzyme pathways, so broadleaf ornamentals, roses, and shrubs remain unharmed even with direct overspray. Several reviewers successfully used it to remove Bermuda grass from around established monkey grass and bleeding heart plants, noting that adding a few drops of dish soap as a surfactant improved results. The product works best on young, actively growing grass under 6 inches tall — tall, mature Johnson grass may only be stunted rather than killed outright.

On the downside, the strong odor was noted by multiple users as unpleasant during mixing and application. A small percentage of customers reported that two applications still failed to kill all grass in their flower beds, suggesting that heavy Johnson grass infestations may require higher application rates or a tank mix partner. The 8 oz bottle treats a limited volume compared to larger concentrate jugs, so acre-scale Johnson grass battles will quickly exhaust this option.

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Arrest Max uses clethodim, a selective post-emergent grass herbicide that targets annual and perennial grasses while leaving clover, alfalfa, and chicory completely unharmed. Whitetail Institute specifically developed this chemistry for food plot environments, but owners report outstanding results on crabgrass in meadow lawns and ryegrass in ornamental beds. The recommended application window is spring or summer once grasses are actively growing, with a pre-spray mowing to 4 inches to ensure uniform coverage.

Users consistently describe a two-phase visual progression: yellow and purple streaking on grass blades within 7 days, followed by complete browning and death by day 13-14. The product requires a crop oil adjuvant (2 oz per gallon) for maximum uptake, and it is rainfast within 1-3 hours. One user with a clover-chicory plot achieved total grass elimination after a second, slightly stronger application at 1.5 oz per gallon after the initial mix was ineffective at maximum dilution.

The main drawback is cost — this pint covers up to 4 acres at the lowest rate, but at the label rate for heavy Johnson grass pressure (1.5 oz per gallon), you will burn through the bottle quickly on medium to large plots. Some users note that Bermuda and fescue resist the first application and require a follow-up with a higher concentration or a different active. Additionally, the product does not have a built-in surfactant, so the adjuvants represent an extra purchase and mixing step.

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Negate 37WG is a dual-powered sulfonylurea herbicide combining rimsulfuron and metsulfuron methyl for broad spectrum post-emergent control on warm season turfgrasses like Bermuda and Zoysia. The 1.5 oz bottle mixes with 1 gallon of water to treat established turf areas up to several thousand square feet. Users report visible weed decline within a week and near-complete clearing by two weeks across grassy weeds like Poa annua and Poa trivalis as well as tough broadleaf species.

The granular-powder formulation dissolves easily in water with no caking or clumping, and the built-in surfactant promotes fast absorption. Multiple golf course and sports field managers confirm its effectiveness for poa annua control, with one user reporting zero poanna after a single fall application. The dual active ingredients provide a broader weed control spectrum than single-active competitors while maintaining selectivity for warm season turf when used at label rates.

On the downside, the 1.5 oz bottle is essentially a one-shot treatment for a typical 1,800 sq ft residential lawn — the entire bottle must be mixed and used within 30 days of reconstitution. At the per-treatment cost, larger properties will need multiple bottles, making it expensive for wide-scale Johnson grass suppression. Additionally, Negate can temporarily stunt Bermuda grass, requiring a post-treatment application of fertilizer and iron for recovery, so timing around active growth windows is critical.

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Ornamec stands out because it arrives pre-mixed with Aqua-Zorb CA surfactant, eliminating the guesswork of tank mixing adjuvants — a feature that saves time and ensures consistent droplet adhesion on waxy Johnson grass leaves. The product is safe for over 400 ornamental plant species, allowing over-the-top spraying in beds containing hostas, boxwoods, hydrangeas, and other broadleaf ornamentals without worry. It claims to stop unwanted grass growth within 48 hours, with full foliar and rhizome control developing over 1-3 weeks.

The focus on professional landscape maintenance is clear: Ornamec targets the toughest perennial grasses including Bermuda, crabgrass, dallisgrass, and quackgrass — all species that share Johnson grass’s rhizome-based growth habit. The ready-to-mix quart treats a meaningful area without requiring additional purchases, and the lack of an offensive odor makes it suitable for spraying around living spaces and gardens.

The primary limitation for Johnson grass specifically is the lack of detailed user reviews confirming results on this particular species. While the chemistry should translate, Ornamec’s premium positioning means you are paying for the surfactant convenience and the 400-plant safety margin rather than raw active ingredient concentration. For large-scale Johnson grass infestations, the per-acre cost may exceed what a more concentrated selective herbicide would deliver with a separate surfactant purchase.

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Fusilade II contains fluazifop-P-butyl, a selective grass herbicide widely used by turf professionals to remove unwanted Bermuda and other perennial grasses from within Zoysia lawns. The application rate is critical — owners consistently report that 0.2 oz per gallon with a non-ionic surfactant kills 90% of Bermuda without damaging Zoysia, while rates above 0.25 oz per gallon cause visible Zoysia cupping and stunting. The chemistry works by interfering with lipid synthesis in grass species, and the slow systemic action shows results within 1-2 weeks as runners die underground.

Multiple users in transition zone states (Nashville, central Texas) confirmed that Fusilade II at the 0.2 oz/gal rate eliminated Bermuda from their Zoysia lawns after 2-3 applications spaced 3-4 weeks apart. The product is effective as a spot treatment or broad spray over turf, and it works on both annual and perennial grasses including ryegrass and foxtail. One owner successfully tank-mixed Fusilade II with triclopyr at 5 ml + 15 ml per gallon to control both Bermuda and broadleaf weeds in a single pass.

The biggest challenge is dialing in the precise rate for your specific turf species and local climate — the label recommends higher rates than what many Zoysia owners find safe. Buyers should start at the low end (0.15 oz/gal) and watch for Zoysia response before committing to a full lawn application. Fusilade II is expensive, and the quart size runs out quickly at standard use rates, making it better suited for spot treatments than whole-acre blanket sprays.

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Target 6 Plus delivers a full 48.2% MSMA (monosodium methanearsonate), an arsenical herbicide that has been a professional-grade tool for golf course superintendents and sod farmers for decades. The 2.5 gallon jug provides massive coverage at a competitive price per gallon, with standard mixing rates around 2 oz per gallon of water for general applications. Users consistently report fast results — visible weed dieback in 2-3 days — and persistence in the root zone that handles tough perennial weeds like dallisgrass and Johnson grass.

The active ingredient has been used since the 1960s for weed control in cotton, turf, and highway rights-of-way, and its track record on rhizomatous grasses is well established. Multiple owners report that a single application at 1.25 tablespoons per 2 gallons eliminated all weeds from their lawns, though overdosing can stress Bermuda grass into early dormancy. The liquid is thick and high-quality, with one user noting a five-year-old bottle remaining effective.

MSMA has significant downsides that limit its recommendation for casual residential use. The product is restricted in several states and cannot be shipped to all addresses — check local regulations before purchasing. It is also non-selective to warm season turf if over-applied, and the 2.5 gallon format is extremely heavy and unsuitable for handheld sprayers. For a single lawn, the volume may represent a 5-10 year supply, and the chemical requires careful storage away from children and pets.