Product Reviews
Best Pasture Weed Killer: The Weed Picks the Product
Arkansas trials give a product, a rate and a month for each weed — and for horsenettle, three consecutive years. Look up the weed before you buy a bottle.
Selective Herbicide for Pasture and Rangeland (dry flowable)
Bayer Cimarron Plus Pasture & Rangeland Herbicide, 2 oz Review
★★★★☆ 4.2/5
our editor rating how we score4.6/5 from 209 shoppers at Amazon — their number, not ours.
$32–$40
Typical price · 2 oz treats a large area — rates are in fractions of an ounce per acre
Affiliate links — see our disclosure. Commissions never influence verdicts.
A sulfonylurea for pasture and rangeland, applied at fractions of an ounce per acre — which makes measuring the single hardest part of using it correctly.
Our Verdict
A different class from the 2,4-D bottles most acreage owners start with. Metsulfuron-methyl is a sulfonylurea, active at very low rates, which is why a 2 oz container treats a serious area and why the rate is stated in fractions of an ounce per acre. That potency is the product's advantage and its main risk: at these rates a rough guess is not a small error, and an accurate scale plus a calibrated sprayer matter more here than with any dilute concentrate. It is a pasture and rangeland product, so the grazing and haying restrictions on the label are the first thing to read — UGA notes restrictions span seven days to a year across products, and a product clear for beef may still restrict dairy. Two further cautions. Sulfonylureas can carry soil residual activity that affects sensitive rotational or interseeded species, so check the label before you overseed clover or a legume into treated ground. And metsulfuron injures many turfgrasses, so this does not belong on a lawn — including bermudagrass in some situations.
✅ Pros
- Very low use rate — a small container covers a large area, so cost per acre is low
- A different mode of action from 2,4-D, useful where broadleaf control has stopped working
- 209 Amazon ratings on a specialist pasture product
- Labelled for pasture and rangeland rather than borrowed from a turf label
⚠️ Cons
- Rates in fractions of an ounce per acre demand an accurate scale — guessing is not a small error here
- Grazing and haying restrictions are product-specific and must be read before use
- Possible soil residual affecting interseeded clover or legumes — check before overseeding
- Injures many turfgrasses; not a lawn product
Product type
Selective Herbicide for Pasture and Rangeland (dry flowable)
Active ingredient
Metsulfuron-methyl 48% + Chlorsulfuron 15%
Price range
$32–$40
Coverage
2 oz treats a large area — rates are in fractions of an ounce per acre
Best for
Broadleaf and brushy weeds on pasture or rangeland, where you have a scale and a calibrated sprayer
our editor rating
4.2 out of 5
Where our facts come from
Label read on EPA's label database
EPA Reg. No. 432-1572
We opened this product's accepted label on EPA's own Pesticide Product Label System — the strongest source available for what a product is registered to do.
What we found when we read it
Full label read 2026-08-02 on EPA PPLS. 'Cimarron Plus Herbicide', EPA Reg. 432-1572 (Envu, formerly Bayer Environmental Science). TWO actives, which our record previously left vague: metsulfuron-methyl 48% AND chlorsulfuron 15%. Grazing, in the label's own words, is unusually permissive at label rates — 'no grazing or hay harvest restrictions for non-lactating or lactating livestock including cattle, horses...' — with the separate and important caution to 'DO NOT graze treated areas until toxic plants are dry and unpalatable to livestock', which is the poisonous-plant hazard our horse pasture guide is about rather than a herbicide residue interval. GRASS INJURY detail recorded 2026-08-20 from University of Arkansas Extension MP44, which names the species rather than leaving it general: "Metsulfuron 60 DF, Pastora and Chaparral are intended for use in bermudagrass. They will damage tall fescue, ryegrass and bahiagrass." Same publication also lists metsulfuron among the products that will kill all clover. So this is a bermudagrass-pasture product with three named grass exclusions, not a general pasture herbicide.
Where this page and the container disagree, the container wins — the label is the legal authority on rates and restrictions. How to read one yourself.
Where This Product Matters
Matched against each state's actual disease, weed and pest pressure.
Montana
Montana hub →Canada thistle and other listed noxious weeds pushing in from unmanaged edges
Application window: June, then late August into September. In a sub-100-day valley there is no third chance
New Mexico
New Mexico hub →Kochia and Russian thistle at the dry margins
Application window: Spring and early autumn; in the south skip the June heat entirely, and in the north the usable autumn window closes by early October
Oregon
Oregon hub →Creeping buttercup (wet valley ground)
Application window: March–May and September–October; the long mild shoulder seasons give more usable spray days than most states get
Washington
Washington hub →Buttercup
Application window: April–May and September–October; WSU caps applications at 80°F, stricter than the 85–90°F ceilings used elsewhere
Wyoming
Wyoming hub →Canada thistle and other listed noxious species moving in from unmanaged edges
Application window: June, then late August into September. UW's own framing is useful: a slow-release application covers a 90 to 100 day growing season, which is roughly the entire Wyoming season
Common questions
Common Questions
How much does Bayer Cimarron Plus Pasture & Rangeland Herbicide, 2 oz cost?
Bayer Cimarron Plus Pasture & Rangeland Herbicide, 2 oz typically runs $32–$40, covering 2 oz treats a large area — rates are in fractions of an ounce per acre.
What does Bayer Cimarron Plus Pasture & Rangeland Herbicide, 2 oz treat?
Bayer Cimarron Plus Pasture & Rangeland Herbicide, 2 oz targets thistle, buttercup, horsenettle, blackberry, multiflora rose.
What is the active ingredient in Bayer Cimarron Plus Pasture & Rangeland Herbicide, 2 oz?
Metsulfuron-methyl 48% + Chlorsulfuron 15%, registered under EPA Reg. No. 432-1572.
What is the biggest downside of Bayer Cimarron Plus Pasture & Rangeland Herbicide, 2 oz?
Rates in fractions of an ounce per acre demand an accurate scale — guessing is not a small error here
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