Active ingredient
Dicamba
Benzoic acid (synthetic auxin)
A synthetic auxin that partners 2,4-D in most three-way products, covering weeds the phenoxy alone handles poorly.
What it does
Broadens a three-way's range — clover, chickweed, knotweed and several weeds that shrug off 2,4-D on its own. It moves in the plant and through soil.
What it does not do
It is not selective by wishful thinking. Dicamba is taken up by roots as well as leaves, so treating turf inside the root zone of a desirable tree or shrub is a real risk rather than a theoretical one.
The label constraint people miss
Root uptake and volatility are the two label constraints that matter to a homeowner. Keep it away from the root spread of anything you want to keep, and treat the temperature ceiling on the label as binding rather than advisory.
Products we review that contain it
Every product below is here because we opened its label — on EPA's own database or the registrant's — and read Dicamba in the ingredient statement. Registration numbers are on each product's page. 1 further product in our catalogue appears to contain it but we could not resolve the label, so it is not listed here — an unread label is not evidence of what is inside the bottle.
Selective Broadleaf Herbicide (hose-end)
Ortho WeedClear Lawn Weed Killer Ready-to-Spray
★★★★☆ (4.4/5)
Classic 3-way broadleaf formula. Rainproof in one hour, visible wilting within days, safe on established turf at labeled rates.
Best for: Whole-lawn broadleaf weed cleanups
$20–$26
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Post-Emergent Herbicide (Crabgrass + Broadleaf)
Ortho Weed B Gon Plus Crabgrass Control
★★★★★ (4.5/5)
The one homeowner bottle that kills crabgrass already up AND common broadleaf weeds — quinclorac is what standard three-way mixes are missing.
Best for: Crabgrass that has already emerged, alongside broadleaf weeds
$34–$42
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Professional Post-Emergent Herbicide
Prime Source Celsius WG Easy Mix Packet
★★★★★ (4.7/5)
The same Celsius WG chemistry in a single-dose packet — heat-safe on warm-season turf, with no bulk purchase and no scale required.
Best for: Stubborn weeds and hot-weather applications on warm-season turf
$15–$20
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Non-Selective Ready-to-Use Herbicide
Spectracide Weed & Grass Killer₂ Ready-to-Use (1 gal)
★★★★☆ (3.8/5)
The cheapest gallon on the shelf, and the ingredient list explains why it must stay off turf: one of the three actives exists specifically to kill grasses.
Best for: Cheap spot treatment of driveways, walkways, gravel and bed edges
$6–$10
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Selective Broadleaf Herbicide (water-soluble, agricultural label)
Alligare Dicamba 4 Herbicide, 2.5 Gallons
★★★☆☆ (3.4/5)
Dicamba works, and it is the herbicide most likely to damage a neighbour's garden through vapour movement hours after you finished spraying.
Best for: Broadleaf control on genuinely isolated acreage, by someone who will read the temperature and buffer guidance
$100–$120
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Selective Broadleaf Herbicide (three-way with MCPA)
Liquid Harvest Lawn Weed Killer Three-Way Concentrate, 32 oz
★★★★☆ (4/5)
A three-way built on MCPA rather than MCPP, which is the substitution most consumer bottles do not make.
Best for: Broadleaf weeds across a whole lawn, where a concentrate's cost per area matters
$34–$42
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Guides that use Dicamba
- Dollarweed: The Weed That Tells You About Your Water
- Best Weed Killer for Centipede: The Sensitive One
- Best Weed Killer for St. Augustine: The Cultivar Decides
- Best Weed Killer for Zoysia: Tolerance Is Not the Problem
- How to Kill Broadleaf Plantain: Read It First
- Chickweed and Henbit: Spring Spraying Is Too Late
Buy for the active, then read the label anyway. Two products with the same active are not interchangeable — concentration, labelled sites and species tolerances all vary, and a three-part registration number means a narrowed label. How to read one in two minutes. Where our page and your container disagree, the container is the legal authority.