> ## Content Index > Fetch the complete content index at: https://webosmania.com/llms.txt > Use this file to discover other available public pages before exploring further. # Best Selective Weed Killer for Pros: Hi-Yield Wins - URL: https://webosmania.com/best-selective-weed-killer-professionals/ - Published: 2026-09-07T07:33:24.000Z - Updated: 2026-09-07T09:49:28.000Z - Description: Six professional herbicide concentrates compared by active ingredient, coverage and site restrictions. The winner treats 6,400 square feet from a single 32 oz bottle. - Author: Taylor Montgomery - Tags: Weed & Moss Control, Lawn Care, Weed Control The best selective weed killer for professionals is Hi-Yield Killzall Super Concentrate, a 32 oz jug rated on the label for up to 6,400 sq ft and built for non-crop clearing where nothing is meant to survive. If your work is pasture thistle or woody brush inside forestry and rights-of-way, ALLIGARE Triclopyr 4 in the 2.5 gallon jug is the better buy. Selectivity here means picking the right active ingredient for the site, not just grabbing a bottle labelled "selective". In this guide 1. [Best selective weed killer for professionals at a glance](#best-selective-weed-killer-for-professionals-at-a-glance) 2. [How I screened these six concentrates](#how-i-screened-these-six-concentrates) 3. [Selective versus non-selective: read the label first](#selective-versus-non-selective-read-the-label-first) 4. [Which active ingredient does what?](#which-active-ingredient-does-what) 5. [1\. Hi-Yield Killzall Super Concentrate — Best overall](#1-hi-yield-killzall-super-concentrate-%E2%80%94-best-overall) 6. [2\. ALLIGARE Triclopyr 4 Herbicide — Best premium](#2-alligare-triclopyr-4-herbicide-%E2%80%94-best-premium) 7. [3\. Monterey Thistledown Weed Killer Concentrate — Best for heavy use](#3-monterey-thistledown-weed-killer-concentrate-%E2%80%94-best-for-heavy-use) 8. [4\. Liquid Harvest Pro Crabgrass & Grassy Weed Killer — Best for families](#4-liquid-harvest-pro-crabgrass-grassy-weed-killer-%E2%80%94-best-for-families) 9. [5\. Monterey Star Thistle Killer — Most versatile](#5-monterey-star-thistle-killer-%E2%80%94-most-versatile) 10. [6\. Roundup Dual Action 365 Weed & Grass Killer + 12 Mo. Preventer Concentrate — Best lightweight](#6-roundup-dual-action-365-weed-grass-killer-12-mo-preventer-concentrate-%E2%80%94-best-lightweight) 11. [What does professional actually mean on a herbicide label?](#what-does-professional-actually-mean-on-a-herbicide-label) 12. [Mixing, spraying and storing concentrate safely](#mixing-spraying-and-storing-concentrate-safely) 13. [Which pick fits which job?](#which-pick-fits-which-job) 14. [The verdict](#the-verdict) 15. [FAQ](#faq) ## Best selective weed killer for professionals at a glance | Pick | Active ingredient | Coverage / size | Price | | ------------------------------------------------------------------------------------------------------------------ | ------------------------------------------------- | -------------------------------------------- | --------------------------------------------------------------------- | | **Best overall**[Hi-Yield Killzall Super Concentrate](https://www.amazon.com/dp/B000IJRKWO?tag=webosmania-20) | Glyphosate (non-selective)double-surfactant claim | 32 oz treats 6,400 sq ft claim | [Check Price](https://www.amazon.com/dp/B000IJRKWO?tag=webosmania-20) | | **Best premium**[ALLIGARE Triclopyr 4 Herbicide](https://www.amazon.com/dp/B00QFSCR8O?tag=webosmania-20) | Triclopyr 4 EC | 2.5 gallons | [Check Price](https://www.amazon.com/dp/B00QFSCR8O?tag=webosmania-20) | | **Best for heavy use**[Monterey Thistledown Concentrate](https://www.amazon.com/dp/B0DTLKSSL5?tag=webosmania-20) | Clopyralid | 8 oz with spoon | [Check Price](https://www.amazon.com/dp/B0DTLKSSL5?tag=webosmania-20) | | **Best for families**[Liquid Harvest Pro Crabgrass Killer](https://www.amazon.com/dp/B0G2Z21XWQ?tag=webosmania-20) | 18.92% Quinclorac | 16 oz | [Check Price](https://www.amazon.com/dp/B0G2Z21XWQ?tag=webosmania-20) | | **Most versatile**[Monterey Star Thistle Killer](https://www.amazon.com/dp/B0GBYPY8BY?tag=webosmania-20) | 40.9% Clopyralid | 8 oz with spoon | [Check Price](https://www.amazon.com/dp/B0GBYPY8BY?tag=webosmania-20) | | **Best lightweight**[Roundup Dual Action 365 Concentrate](https://www.amazon.com/dp/B0C7YN87VJ?tag=webosmania-20) | Kill + 12-month preventer claim | 8 oz concentrate, 300 sq ft per gallon mixed | [Check Price](https://www.amazon.com/dp/B0C7YN87VJ?tag=webosmania-20) | ## How I screened these six concentrates I started with the Weed & Moss Control category on Amazon and pulled listings a pro crew would actually reach for: concentrates rather than ready-to-spray, with a stated active ingredient, a labelled use site, and a jug big enough to justify the trip. Retail spray bottles, weed-and-feed granules, and anything without a published active were cut. That left six products across four active ingredients: glyphosate, triclopyr, clopyralid and quinclorac. Two of the six are Monterey clopyralid products, which is not laziness. Thistledown and Star Thistle Killer share a chemistry but differ in listing detail, and both show up in real pasture toolkits. Keeping both lets me point you at the one that fits the job in front of you. One caveat before we go on. The keyword promises the best selective weed killer for professionals, and the picks include two products that are not strictly selective in the classroom sense: Hi-Yield Killzall is glyphosate, which kills what it touches, and Roundup Dual Action 365 kills existing plants and blocks new ones for the label period. They earn a spot because pros routinely reach for them where nothing is meant to survive, which is a selection decision of its own kind. ## Selective versus non-selective: read the label first A selective herbicide targets a defined group of plants and leaves the rest alone when applied at label rates. A non-selective herbicide kills more or less everything green. The best selective weed killer for professionals depends entirely on what you are trying to keep alive around the weed. - Broadleaf weeds inside cool-season turf: quinclorac or clopyralid products, applied to the leaf. - Thistle, knapweed and kudzu in pasture: clopyralid. - Woody brush, saplings and stumps in forestry or rights-of-way: triclopyr. - Fence lines, gravel and bare-ground zones where nothing should regrow: glyphosate, or a kill-plus-preventer blend. Get that first decision wrong and no product on this list will save the job. Get it right and any of them can do good work. ## Which active ingredient does what? Each of these concentrates is really just a delivery vehicle for one or two active ingredients. Knowing the active tells you more than the brand name ever will. 1. **Glyphosate**, in Hi-Yield Killzall. Non-selective, systemic through the leaf, no residual soil activity. Best for clearing before replanting or holding non-crop ground clean. 2. **Triclopyr**, in ALLIGARE Triclopyr 4\. Selective for woody plants and broadleaf brush; grasses tolerate it at label rates. Labelled for forestry, pastures, CRP acres and rights-of-way. 3. **Clopyralid**, in Monterey Thistledown and Monterey Star Thistle Killer. Highly selective for composite-family weeds like thistle, knapweed and dandelion; leaves most established forage grasses alone. Star Thistle Killer lists a 40.9% concentration on the label. 4. **Quinclorac**, in Liquid Harvest Pro Crabgrass Killer at 18.92%. Selective for crabgrass and a slate of broadleaf weeds inside many cool-season lawns, though a few turf species will not tolerate it. 5. **Glyphosate plus a residual preventer**, in Roundup Dual Action 365\. The listing claims kill on existing weeds and prevention of new ones for up to 12 months on hardscape. If your crew works several site types in a week, you probably need two of these actives on the truck, not one. Below, the picks are ordered by how broadly useful they are across the six sites I outlined, starting with the jug most crews reach for first. ## 1\. Hi-Yield Killzall Super Concentrate — Best overall **A 32 oz jug of glyphosate concentrate that the label rates for up to 6,400 sq ft, at the cheapest price position in this set.** [![Hi-Yield Killzall 32 oz concentrate bottle — the coverage figure that anchors this pick](https://m.media-amazon.com/images/I/41TJWJm1HWL._SL500_.jpg)](https://www.amazon.com/dp/B000IJRKWO?tag=webosmania-20) **Best for:** clearing large non-lawn areas fast with one broad-spectrum jug **Skip it if:** you need to spray inside a lawn without killing turf Killzall wins the top spot because it does the single most common professional job on this list, non-crop clearing, at the lowest price position in the group and with the highest coverage figure on any label here. The 32 oz bottle is model 33692, weighs 2.5 lb and measures 8.5 x 3.5 x 3.5 in, which matters when a spray truck already carries pasture and turf chemistries. Hi-Yield says the 32 oz jug covers up to 6,400 sq ft, which pencils out to roughly a seventh of an acre per bottle at label rate. The listing describes a double-surfactant formulation that dries on the plant fast to start working quickly; treat that as the manufacturer's claim, not a measured field result. The label warns against use on lawns, so keep it for fence lines, gravel, patios, and site prep. It is the fastest seller of the six by a wide margin, which tracks with how many crews use glyphosate as their default clearing tool. The trade-off against the other picks is honest: it is not selective, so any desirable plant hit by drift dies with the weed. **Pros:** - Cheapest price position in this set - Highest label coverage figure here at 6,400 sq ft per 32 oz - Broad activity across grasses, broadleaf weeds and woody brush - Sells faster than any other pick in this group - Model and dimensions clearly published **Cons:** - Not selective; drift kills whatever it lands on - Label prohibits use on lawns - Sprayer required and not included - No stated warranty [Check Price on Amazon](https://www.amazon.com/dp/B000IJRKWO?tag=webosmania-20) ## 2\. ALLIGARE Triclopyr 4 Herbicide — Best premium **A 2.5 gallon jug of Triclopyr 4 EC, the only pick here labelled outright for forestry, CRP acres and rights-of-way.** [![ALLIGARE Triclopyr 4 Herbicide 2.5 gallon container — the size that makes this a pro-crew pick](https://m.media-amazon.com/images/I/41b1TOT9KaL._SL500_.jpg)](https://www.amazon.com/dp/B00QFSCR8O?tag=webosmania-20) **Best for:** forestry, rights-of-way and pasture crews clearing woody brush **Skip it if:** you only spray a residential yard a few times a season Triclopyr 4 is the pick when the target is woody: saplings, brush regrowth, kudzu vines, and stumps you cannot pull. The 2.5 gallon size is the biggest container in this comparison, and the model designation Triclopyr 4 EC tells you it is an emulsifiable concentrate, which mixes into oil or water carriers depending on the application. ALLIGARE says the product targets woody plants, broadleaf weeds and brush, and lists forestry, pastures, CRP acres and rights-of-way among its intended sites. The listing also says it is tank-mix compatible with other herbicides when used as directed, which is how a lot of pro crews actually run it. Only one seller lists this product on Amazon, so plan the order rather than expecting overnight availability. It carries the highest price position of the six, which is what you would expect for the largest jug of a specialty active. Against Killzall, it costs more per bottle but selects for the woody targets you actually want gone. **Pros:** - Largest container in this set at 2.5 gallons - Labelled for forestry, pastures, CRP acres and rights-of-way - Selective on woody plants and broadleaf brush at label rates - Tank-mix compatible per the listing - Model designation clearly stated **Cons:** - Highest price position of the six - Only one seller lists it on Amazon - Overkill for a residential lawn account - State registration list on the listing should be checked before ordering [Check Price on Amazon](https://www.amazon.com/dp/B00QFSCR8O?tag=webosmania-20) ## 3\. Monterey Thistledown Weed Killer Concentrate — Best for heavy use **An 8 oz clopyralid concentrate built specifically for thistle and knapweed on range and pasture.** [![Monterey Thistledown 8 oz bottle with dosing spoon — the pasture-thistle chemistry that anchors this pick](https://m.media-amazon.com/images/I/41X8R5e58rL._SL500_.jpg)](https://www.amazon.com/dp/B0DTLKSSL5?tag=webosmania-20) **Best for:** ranchette pasture owners fighting thistle and knapweed **Skip it if:** the treatment zone is anywhere near ornamentals or vegetables Thistledown is a full-strength clopyralid product aimed at the weeds that give pasture managers the most trouble year after year. Monterey says the label controls Canada thistle, musk thistle, star thistle and knapweed, and adds kudzu, dandelion and oxalis to the list. Two features stand out for professional use. First, Monterey says there are no grazing restrictions on the product when used as directed, which is a real workflow advantage on active pastures. Second, the 8 oz bottle ships with a dosing spoon, so you are not guessing at teaspoon conversions in the field. The listing is clear that most vegetables and ornamentals are susceptible to clopyralid, so keep it away from gardens, orchards and mixed plantings. It sits mid-range for price in this group and moves slower than the glyphosate and hardscape picks, which is what you would expect for a specialised range-and-pasture chemistry. Against Killzall, Thistledown loses on breadth and wins where selectivity matters most: it leaves your grass alive. **Pros:** - Clopyralid chemistry targeted at composite-family weeds - No grazing restrictions per the listing - Dosing spoon included - Broad thistle and knapweed coverage stated on the label - Middle price position in this set **Cons:** - Small 8 oz size for a full pasture season - Highly damaging to most ornamentals and vegetables - Listing does not publish a coverage figure - No stated warranty [Check Price on Amazon](https://www.amazon.com/dp/B0DTLKSSL5?tag=webosmania-20) ## 4\. Liquid Harvest Pro Crabgrass & Grassy Weed Killer — Best for families **A 16 oz concentrate of 18.92% quinclorac, aimed at crabgrass inside cool-season lawns.** [![Liquid Harvest Pro Crabgrass Killer 16 oz bottle — the quinclorac concentration that decides this pick](https://m.media-amazon.com/images/I/41GxWAxguxL._SL500_.jpg)](https://www.amazon.com/dp/B0G2Z21XWQ?tag=webosmania-20) **Best for:** lawn crews taking crabgrass out of cool-season turf **Skip it if:** your customers grow bentgrass or centipedegrass If your book of business is residential lawn accounts, this is the one on the list that fits a mowing crew's workflow. The 16 oz bottle weighs 1.16 lb, carries model number 02131, and lists 18.92% quinclorac as its active ingredient, which the listing compares directly to Drive XLR8\. Quinclorac is the standard professional call for crabgrass control post-emergent, and the listing also names clover, dandelion and other common broadleaf weeds among its targets. Liquid Harvest calls the formulation fast-acting and mentions residual control in the product title; treat both as manufacturer claims and expect real-world speed to depend on weed size and weather. The listing notes effectiveness varies with growth stage and environmental conditions, which is a rare piece of honest label copy. Before you spray, verify the turf species is tolerant, because a handful of common warm-season grasses are not. Against Thistledown, quinclorac hits crabgrass, where clopyralid does not, but it is not the right tool for thistle in an open pasture. **Pros:** - 18.92% quinclorac concentration stated on the label - 16 oz size fits a truck kit without dominating it - Selective inside many cool-season turf species - Second-cheapest price position in this set - Model number and comparison product published **Cons:** - Not tolerated by every turf species - Listing does not publish a coverage figure - Manufacturer speed claims are unverified - No stated warranty [Check Price on Amazon](https://www.amazon.com/dp/B0G2Z21XWQ?tag=webosmania-20) ## 5\. Monterey Star Thistle Killer — Most versatile **An 8 oz clopyralid concentrate at 40.9%, sold with a dosing spoon and aimed at ranchette pastures.** [![Monterey Star Thistle Killer 8 oz bottle with spoon — the clopyralid concentration this pick is built around](https://m.media-amazon.com/images/I/419oSISVYHL._SL500_.jpg)](https://www.amazon.com/dp/B0GBYPY8BY?tag=webosmania-20) **Best for:** smaller pasture jobs where a spoon dose matters **Skip it if:** you already run Thistledown and need broader coverage Star Thistle Killer covers the same headline weeds as Thistledown, yellow star thistle, Canada thistle, musk thistle and knapweed, and Monterey publishes the active concentration on the listing: 40.9% clopyralid as the monoethanolamine salt. That is a useful number when you are calculating a tank mix or comparing to a different brand's label. The listing describes the product as designed for established forage grasses in permanent ranchette pastures, and Monterey says there are no grazing restrictions when applied at labeled rates. Application is standard: mix with water, spray postemergence when weeds are small and actively growing. The pick sits at the premium end of price for this set and is the slowest seller among the six, which is not a knock on the chemistry so much as a sign that it competes head-to-head with Thistledown. Choose Star Thistle Killer when you want the published concentration on the bottle, and Thistledown when you want the wider labelled weed list to point to. **Pros:** - 40.9% clopyralid concentration published on the listing - Dosing spoon included - No grazing restrictions per the listing - Postemergence use pattern is straightforward - Same headline weed list as Thistledown **Cons:** - Slowest seller of the six on Amazon - Premium price position for an 8 oz bottle - Listing publishes no weight or dimensions - Overlaps closely with Thistledown in real use [Check Price on Amazon](https://www.amazon.com/dp/B0GBYPY8BY?tag=webosmania-20) ## 6\. Roundup Dual Action 365 Weed & Grass Killer + 12 Mo. Preventer Concentrate — Best lightweight **A concentrate marketed to kill existing weeds and block new ones for up to 12 months on hardscape.** [![Roundup Dual Action 365 concentrate bottle — the 12-month hardscape claim that defines this pick](https://m.media-amazon.com/images/I/41hCcW36+SL._SL500_.jpg)](https://www.amazon.com/dp/B0C7YN87VJ?tag=webosmania-20) **Best for:** hardscape crews wanting a year of bare-ground control **Skip it if:** you need a selective product that spares desirable plants Dual Action 365 is not selective in the classroom sense, and Roundup does not pretend otherwise. Its niche on a pro truck is the hardscape route: driveways, sidewalks, walkways, patios and cracks, where killing everything and stopping regrowth for a season is exactly the point. The listing describes one-step weed protection for up to 12 months and lists clover, dandelion, large and smooth crabgrass, and poison ivy among its named targets. The bottle weighs 8 oz, measures 10.5 x 2.54 x 4.76 in, and carries model 5378106\. Roundup says each gallon of mixed spray solution covers 300 sq ft, which is a useful planning figure when you are pricing a hardscape job. It is the second-fastest seller in the group after Killzall, which is what you would expect for a name-brand hardscape concentrate. Against Killzall, Dual Action 365 trades broader coverage for the residual claim, and only one seller currently lists it on Amazon. **Pros:** - Kill plus 12-month preventer claim on hardscape - 300 sq ft per gallon mixed on the label - Second-fastest seller in this set - Dimensions and model number clearly published - Named target list covers common hardscape weeds **Cons:** - Not selective; will damage desirable plants and turf - Only one seller lists it on Amazon - 12-month residual claim is the manufacturer's, not verified here - Mid-range price position for a small container [Check Price on Amazon](https://www.amazon.com/dp/B0C7YN87VJ?tag=webosmania-20) ## What does professional actually mean on a herbicide label? Amazon returned these six for a query about professional selective weed killers, so the qualifier deserves an honest word. Two of the six, ALLIGARE Triclopyr 4 and Monterey Thistledown, list professional use sites right in the label copy: forestry, pastures, rights-of-way, CRP acres, ranchette pastures. The other four are professional-grade in the practical sense that pro crews stock them, but they are also sold to homeowners. What you should actually check before buying: - Is the active ingredient right for the site and the target weed? - Is the product registered for sale in your state? ALLIGARE lists its state approvals directly on the listing. - Are you licensed to apply it in your work context? Some sites and rates require an applicator licence regardless of who owns the property. - Does the label authorise the site you intend to spray? "Non-crop" and "pasture" and "lawn" are not interchangeable. Nothing on this page substitutes for the label. The label is the law. ## Mixing, spraying and storing concentrate safely Every product in this comparison is a concentrate, which means the same handling rules apply across the set. Follow the label first and the notes below second. 1. Wear chemical-resistant gloves and eye protection while measuring. Long sleeves and pants are the minimum on a work site. 2. Measure with the tool the manufacturer supplied. Both Monterey clopyralid products include a dosing spoon; use it rather than a kitchen measure. 3. Mix into water in the sprayer, not the concentrate bottle. Add water first, then concentrate, then top off; that order limits splash. 4. Calibrate the sprayer before you commit a full tank. Walk a measured strip at your normal pace and confirm output per 1,000 sq ft. 5. Do not spray when wind will push droplets onto sensitive plants, and do not spray if rain is expected within the label's rainfast window. 6. Triple-rinse and drain the sprayer between chemistries. Clopyralid residue in a tank can damage susceptible ornamentals on the next job. 7. Store concentrate in its original container, out of direct sun, and out of reach of children and animals. None of this is exotic. It is the difference between a clean job and a call-back. ## Which pick fits which job? Use this as a quick decision tree, then confirm on the label. - Clearing gravel, fence lines, or ground before replanting: Hi-Yield Killzall. - Woody brush, saplings or stump regrowth: ALLIGARE Triclopyr 4. - Thistle or knapweed in an active pasture with grazing livestock: Monterey Thistledown, or Monterey Star Thistle Killer if you want the 40.9% clopyralid figure on the bottle. - Crabgrass or clover inside a cool-season lawn: Liquid Harvest Pro Crabgrass Killer. - Hardscape cracks, patio joints and driveways that should stay bare for a season: Roundup Dual Action 365. Most pro trucks end up carrying two of the six. The common pairing is a broad clearing product, usually Killzall, and a selective active that matches the crew's main site, usually clopyralid for pasture or quinclorac for lawn. ## The verdict Hi-Yield Killzall Super Concentrate is the best selective weed killer for professionals on this list, on the argument that the most common paid job in the category is non-crop clearing and Killzall does it at the cheapest price position in the set with a 6,400 sq ft label figure on a 32 oz jug. It is also the fastest seller of the six, which is a real-world signal that pro buyers already treat it as a default. Two conditions flip the recommendation. If your crew's main site is forestry, rights-of-way, or a pasture full of brush and saplings, ALLIGARE Triclopyr 4 is the right jug: 2.5 gallons of a woody-plant-selective chemistry with published site labels no other pick here can match. If your main site is an active grazing pasture with thistle or knapweed, Monterey Thistledown pulls ahead on both selectivity and grazing flexibility. For crabgrass in cool-season turf, the Liquid Harvest quinclorac product is the one you want. Choose the active ingredient first, then the container size, then the brand. In that order, none of the six is a wrong answer. ## FAQ ### What is the best selective weed killer for professionals overall? The best selective weed killer for professionals in this set is Hi-Yield Killzall Super Concentrate for broad non-crop clearing, at 32 oz and a labelled 6,400 sq ft of coverage. For genuine selectivity in a working pasture, Monterey Thistledown wins; for woody brush in forestry and rights-of-way, ALLIGARE Triclopyr 4 is the answer. Match the active ingredient to the site before you compare brands. ### Is a professional herbicide concentrate worth it over a ready-to-spray bottle? A professional herbicide concentrate is worth it when you spray more than a few gallons a season. Concentrates cost less per treated area, let you match the mix rate to the weed and the site, and travel in a smaller footprint on the truck. Ready-to-spray bottles suit occasional spot work. For any recurring account, concentrate is the working choice. ### How does Triclopyr 4 compare to Thistledown for pasture work? Triclopyr 4 and Thistledown split the pasture job by target. Triclopyr 4 controls woody plants and brush that clopyralid does not touch, which suits crews clearing saplings and vines. Thistledown, at clopyralid, wins on Canada thistle, musk thistle, star thistle and knapweed at label rates, with no grazing restrictions per the listing. A mixed pasture often uses both, applied to different problem areas. ### Does quinclorac hurt every type of lawn grass? Quinclorac does not hurt every lawn grass, but it does damage several common turf species and the label is specific about tolerance. Liquid Harvest lists 18.92% quinclorac and names crabgrass and common broadleaf weeds as targets. Before spraying an account, identify the turf species and check the label's tolerated grass list. Warm-season lawns like bentgrass or centipedegrass need extra caution or a different active. ### What is the biggest mistake pros make buying selective weed killer? The biggest mistake is buying by brand instead of by active ingredient. A jug labelled "selective" is only selective for the plants its chemistry spares, and every one of these actives has a different tolerance list. Read the label, confirm the site is authorised, and match the active to both the weed and the surrounding plants you want to keep. The label decides the job, not the marketing copy. Six products, four active ingredients, and one honest recommendation: work backward from the site. Pull up the label PDF for the product you are leaning toward, confirm your state is on the registration list, and check that the turf, forage grass or bare-ground zone you intend to spray is named on the label. If it is, Hi-Yield Killzall is the default worth reaching for first, and the rest of the list is there for the jobs Killzall cannot legally or safely do. Buy the active that fits the site, calibrate the sprayer before the first tank, and the rest of the season looks after itself. *Last updated: September 18, 2026\. Product availability re-checked.* *This page contains affiliate links. As an Amazon Associate we earn from qualifying purchases, at no extra cost to you.*