7 Best Herbicide For Johnsongrass | Skip the Dilution Guess

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The standout feature of Target 6 Plus is its 48.3% MSMA concentration, an organic arsenical that delivers unmatched systemic control on Johnsongrass rhizomes. Users report visible wilting within two to three days in warm temperatures, with complete top-kill in under a week. The 2.5-gallon jug provides enough volume for multiple seasons on a residential property, and the recommended mix rate of two ounces per gallon hits Johnsongrass hard without excessive waste.

This product is labeled for cotton, golf courses, sod farms, and highway rights-of-way, which speaks to its professional-grade formulation. Because MSMA is a restricted-use pesticide in some states (banned for residential lawns in certain regions), buyers should verify local regulations before purchasing. The concentrate stores well for years if kept in a cool, dry place, as confirmed by a five-year-old bottle that still produced results.

When used at one ounce per gallon with ammonium sulfate (AMS) and a surfactant, it also eliminates goosegrass, nutsedge, and Bahiagrass without severe Bermudagrass injury at the correct rate. The downside is the mixing precision required — over-application stresses warm-season turf noticeably, so follow the label exactly.

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Dow Milestone contains aminopyralid, a selective auxin-type herbicide that targets broadleaf weeds and certain grasses in permanent grass pastures, rangeland, and CRP acres. Its coverage of four to seven acres per 32-ounce bottle makes it a high-efficiency choice for large-scale Johnsongrass suppression in non-cropland settings. The chemical is rainfast quickly and translocates to roots for lasting control.

This formulation is not for use on residential lawns or near vegetable gardens because aminopyralid can persist in hay and manure, causing damage to sensitive crops. The shelf life of three to five years in proper storage adds long-term value for property managers who need a reliable rotational tool. Users applying it on grazed areas report clean pastures within one season when timed with active growth.

One limitation is that aminopyralid does not provide the same speed of burndown as glyphosate or MSMA — expect a two- to three-week window for full symptom expression. Pairing it with a non-ionic surfactant improves uptake on thicker Johnsongrass leaves.

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Quinclorac 75 DF is a dry flowable herbicide that excels at controlling crabgrass and Johnsongrass in established Bermudagrass and zoysia lawns. The 75% active ingredient concentration means a little goes a long way — the maximum mix rate is 0.367 ounce per gallon of water (about 1.4 teaspoons). It works by inhibiting cellulose synthesis, causing growing points to fail and the plant to collapse from the inside.

This product is labeled for athletic fields, schools, commercial properties, and residential turf, making it a versatile option for property managers. It requires a surfactant for optimal performance and works best when daytime temperatures are above 60°F. Users report that a single application stops crabgrass germination for several weeks when applied early post-emergent.

One drawback is that quinclorac can cause temporary yellowing on certain turf varieties, particularly St. Augustinegrass and centipedegrass, so it is not recommended for those lawn types. The dry flowable formulation requires thorough agitation in the spray tank to prevent settling.

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RoundUp Promax is a concentrated glyphosate formulation designed for non-selective spot treatment, turf renovation, and brush control. The 1.67-gallon jug treats an area equivalent to six quarts of standard RoundUp Pro, making it a cost-effective choice for clearing large patches of Johnsongrass before reseeding. Its rainfast window of 30 minutes is the shortest among the non-selective options, ideal for unpredictable weather windows.

This product works by inhibiting the EPSPS enzyme, which shuts down protein production and kills the entire plant, including rhizomes, over one to two weeks. It is perfect for driveways, fence lines, and garden beds where you want zero regrowth. The low-foaming formula ensures consistent spray patterns even in backpack sprayers.

The obvious limitation is that glyphosate kills any green vegetation it contacts, so it cannot be used near desirable turf or ornamentals without extreme care. Use a shield or wiper applicator to avoid drift damage.

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Whitetail Institute Arrest Max uses clethodim, a selective grass herbicide that kills Johnsongrass and other annual/perennial grasses without harming clover, alfalfa, or chicory food plots. The 16-ounce pint treats up to four acres, and the recommended mix rate is one ounce per gallon of water with two ounces of crop oil. Users consistently report that clover fields cleared of grass recover vigorously within a month.

This product is rainfast in one to three hours depending on humidity, and it works best when applied to actively growing grass in spring or summer. The systemic action takes time — expect two to three weeks before grass turns yellow and dies. Northern Michigan users confirm it eliminates crabgrass and quackgrass alongside Johnsongrass in mixed-infestation food plots.

The active ingredient clethodim will also kill chicory, so avoid spraying over mixed forage plots unless you want to remove that component. It requires a crop oil concentrate or non-ionic surfactant for full efficacy on tougher grass species.

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Liquid Harvest Mesotrione is a selective pre- and post-emergent herbicide that controls Johnsongrass in cool-season turf species like Kentucky bluegrass, tall fescue, and perennial ryegrass. It works by inhibiting the HPPD enzyme, causing susceptible plants to bleach white before dying. The 8-ounce bottle treats a standard lawn and can be used at seeding time without harming new grass establishment.

This product targets 46 broadleaf and grass species including barnyardgrass, crabgrass, and dandelion. It requires activation water within 10 days — if no rain falls, apply 0.15 inches of irrigation. Users in Arizona and other arid climates report excellent weed suppression in rock landscapes when used as a pre-emergent barrier. The liquid concentrate mixes easily and stays stable in solution.

The main caution is that over-application can cause temporary bleaching on St. Augustinegrass and Bentgrass. It is also less effective on mature, established Johnsongrass compared to MSMA or glyphosate, so use it as part of an early-season suppression program rather than a rescue treatment.

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Hi-Yield Turf & Ornamental Weed & Grass Stopper is a granular pre-emergent herbicide designed to prevent weed and grass seeds from germinating in established lawns and ornamental beds. The 12-pound bag covers a moderate-sized property and is applied with a standard broadcast spreader. It creates a chemical barrier in the top inch of soil that stops Johnsongrass before it emerges.

This product is best used in the spring when soil temperatures reach 55°F, before Johnsongrass seeds germinate. It will not control existing rhizomes or actively growing plants, so it functions as a prevention tool rather than a cure. Users who apply it consistently for two consecutive springs report significantly reduced Johnsongrass pressure over time.

The granular formulation makes application straightforward without spray drift concerns, but it requires watering-in within 24 hours for activation. It is not effective on heavy clay soils where water penetration is slow, and it will not control already established perennial weeds.