Specs are compiled from manufacturer listings and verified buyer reviews and can change over time — please confirm the key details on the product page before buying.
When poison ivy, poison oak, or tough brush takes over your property, generic weed sprays often fall short — leaving you to fight the same stubborn patches season after season. This guide cuts through the marketing and lines up the specific concentrates and ready-to-use formulas that are actually labeled to kill these woody vines and brush, so you buy the one that fits your yard’s size and your patience for mixing.
I’m Rikta — the founder and writer behind Lawn Gear Lab. This guide is built by comparing the manufacturers’ published specifications and the patterns across verified customer reviews, so you get each pick’s real strengths and trade-offs instead of marketing spin.
From concentrated jugs that cover a whole acre to ready-to-use spray bottles for quick spot treatments, here is a detailed breakdown of the six best weed and poison ivy killer options on the market right now.
Quick Picks
- Bonide 332 Herbicide Poison Ivy & Brush Killer Bk-32 Concentrate, 128 oz — Best Overall
- Roundup Weed & Grass Killer₄ Concentrate, 1 gal — Ultimate Value
- Pro Brush & Poison Ivy Killer – 32oz – (Compare to Crossroad) Concentrate — Premium Performer
- Roundup Poison Ivy Plus Tough Brush Killer₂ Concentrate, 32 fl. oz. — Fast Starter
- Ortho 0475010 MAX Poison Ivy & Tough Brush Killer Ready-To-Use, 24-Ounce — Ready-to-Use
- Neudorff Weed and Grass Killer, 32 oz Ready-to-Use — Fastest Kill
How To Choose The Best Weed And Poison Ivy Killer
Not every weed killer can tackle poison ivy. You need a formula with active ingredients like triclopyr, 2,4-D, or dicamba that penetrate the waxy leaves and travel down to the root system. Here are the main factors that separate a one-season fix from a total solution.
Concentrate vs. Ready-to-Use
Concentrates (like 32 oz or 128 oz jugs) let you mix your own batch, which gives you more coverage per dollar but requires a sprayer and careful measuring. Ready-to-use bottles screw onto a hose or have a trigger sprayer — you pull and spray, no mixing, ideal for small patches or quick spot treatments.
Active Ingredients and What They Target
Triclopyr is the heavy hitter for woody vines like poison ivy and poison oak. 2,4-D and dicamba add broadleaf weed control. A mix of these in one bottle means you can knock out brush, vines, and lawn weeds in a single pass.
Coverage Area and Rainfast Time
Check how many square feet a bottle covers, especially for concentrates that you dilute. Also look at how fast the product is rainproof — some dry in 30 minutes, others need 2-3 hours. If a storm is coming, a fast rainfast window matters.
Quick Comparison
On smaller screens, swipe sideways to see the full table.
| Model | Best For | Liquid Volume | Item Weight | Active Ingredients | Amazon |
|---|---|---|---|---|---|
| Bonide 332 | Large-scale root kill | 128 fl oz | 8.6 lbs | MCPA, Triclopyr, Dicamba | Amazon |
| Roundup Weed & Grass Killer₄ | Ultimate value per gallon | 1 gal (128 fl oz) | 128 oz | Triclopyr, Fluazifop, Diquat | Amazon |
| Pro Brush & Poison Ivy Killer | Triclopyr + 2,4-D combo | 32 fl oz | 2.5 lbs | Triclopyr, 2,4-D | Amazon |
| Roundup Poison Ivy Plus Tough Brush Killer₂ | Fast-acting concentrate | 32 fl oz | 8 oz | Triclopyr, Fluazifop, Diquat | Amazon |
| Ortho MAX Poison Ivy & Tough Brush Killer | Ready-to-use spot spray | 24 fl oz | 1.13 lbs | Non-selective broad spectrum | Amazon |
| Neudorff Weed and Grass Killer | Fastest visible results | 32 fl oz | 32 oz | Ammoniated Salts of Fatty Acids | Amazon |
In‑Depth Reviews
1. Bonide 332 Herbicide Poison Ivy & Brush Killer Bk-32 Concentrate, 128 oz
Buyers report this three-ingredient concentrate kills poison ivy, oak, and sumac at the roots permanently — making it the best choice for large properties with woody vines.
You get permanent root kill from a serious punch: 13.72% MCPA, 1.56% triclopyr (a herbicide that targets woody vines by penetrating waxy leaves), and 1.35% dicamba (a broadleaf weed killer) — all inside a 128-fluid-ounce jug. At 8.6 pounds, it is the heaviest option here and holds 128 fl oz versus the Ortho ready-to-use at 24 fl oz, so you are buying for entire seasons of coverage, not a single afternoon.
The trade-off is patience and prep. Owners mention it requires a hot, sunny day with 48 hours of no rain, and you must saturate dry leaves and stems. A few owners found that stubborn ground ivy took two or three applications before they saw complete results. On the plus side, the formula is selective enough to leave lawn grasses like bluegrass, fescue, and Bermuda untouched when used as directed.
Think of this as the long-term investment: mix with water in a tank or hose-end sprayer and cover over 240 types of weeds. The concentrate format also works as a stump killer — just paint undiluted product onto freshly cut stumps.
Real Coverage Power
- 128 fl oz concentrate treats massive areas; 8.6 lbs of product lasts seasons
- Three active ingredients (MCPA, triclopyr, dicamba) attack roots for permanent kill
- Safe for many lawn grasses when applied correctly
The Real Catch
- Requires rain-free window up to 48 hours for best results
- Stubborn ground ivy may need 2-3 treatments
- Heavy 8.6 lb jug is awkward to handle
Grab this if: you have acres of poison ivy, oak, or brush and want a single concentrate that kills roots permanently.
Look elsewhere if: you need a quick spot spray this afternoon — this concentrate needs mixing and a good weather window.
2. Roundup Weed & Grass Killer₄ Concentrate, 1 gal
A full gallon of concentrated Roundup that dries rainproof in 30 minutes — faster than any other product here, which is a huge advantage when afternoon storms roll in.
This is the largest liquid volume in the list at a full gallon (128 fluid ounces), and customers note it is “very effective weed killer” that requires careful handling with long sleeves, gloves, and a full-face respirator. The active blend includes triclopyr, fluazifop-P-butyl (a grass-selective herbicide), and diquat dibromide (a contact killer that damages plant cells on touch) — the same core chemistry that drives the smaller Roundup Poison Ivy Plus bottle, scaled up to industrial volume.
It is rainproof in as fast as 30 minutes. That is a huge practical advantage if you are spraying in a region with unpredictable afternoon storms. The concentrate mixes at a rate of one gallon of spray solution per 300 square feet, so the whole gallon covers a substantial perimeter of fence lines, driveways, and flower beds.
One honest limit reviewers mention: it kills existing weeds but does not prevent new ones from popping up. That is standard for non-selective herbicides, but worth factoring into your season plan.
Volume Leader: At 128 oz it matches the Bonide jug’s size but uses a slightly different active mix — both are concentrates, and this Roundup is rainproof in 30 minutes while Bonide buyers mention a 48-hour rain-free window for best results.
Best for: anyone who needs maximum concentrate volume and fast rainproof protection for large flower beds, walkways, and fence lines.
skip it if: you don’t want to mix your own spray — this is a concentrate and requires a tank or hose-end sprayer.
3. Pro Brush & Poison Ivy Killer – 32oz – (Compare to Crossroad) Concentrate
This dual-active concentrate (triclopyr plus 2,4-D) works in both warm and cool weather — a rare flexibility that means you can apply it during the growing season or in dormant periods.
Reviewers point out plants “droop in hours, full yellowing/browning in weeks.” At 32 fluid ounces (2.5 pounds), this is more concentrated pound-for-pound than many consumer options — the label calls for 1.3 to 5.3 ounces per gallon of water, so a single bottle can yield two full treatments.
A real standout detail from experienced buyers: adding a surfactant (a soap-like substance that helps the spray spread and stick to leaves) significantly boosts effectiveness. The formula also works in both cool and warm weather, and you can apply it during the growing season or in dormant periods. That flexibility is rare among poison ivy killers, which often demand warm, active growth conditions.
The catch is toxicity. Multiple reviewers emphasize that this is very strong stuff — “be careful where you use it and don’t get it on you or breathe the fumes.” It requires full protective gear and careful application around desirable plants. Compared to the Ortho ready-to-use, which needs 2 hours to dry, this concentrate demands more safety steps.
Why It Stands Out
- Triclopyr + 2,4-D combo effective in warm and cool weather
- One bottle yields two treatments when mixed at 1.3-5.3 oz per gallon
- Can be applied during dormant season, not just active growth
What To Watch
- Strong chemical requires full protective gear and careful handling
- May need a third application for deep root systems
- Adding surfactant is recommended by buyers for best results
Reach for this if: you want a strong triclopyr/2,4-D concentrate in a manageable 32 oz size that works across seasons.
Look elsewhere if: you are sensitive to potent chemical fumes or want something milder for spot treatments around kids and pets.
4. Roundup Poison Ivy Plus Tough Brush Killer₂ Concentrate, 32 fl. oz.
It weighs only 8 ounces and holds 32 fluid ounces of triclopyr-based concentrate, while the Bonide jug weighs 8.6 pounds, making it the easiest heavy hitter to pour and carry.
The formula is a mix of triclopyr 2.5%, fluazifop-P-butyl 2.0%, and diquat dibromide 1.5%. Shoppers say it “kills plants with leaves; most die with 1 application, tough ones need more,” making it a reliable starter for anyone with a medium-sized yard.
It is rainproof in as fast as 30 minutes — tying the larger Roundup gallon for the fastest rainfast time here. That means you can spray in the morning and not worry if a light shower rolls through later. The concentrate covers up to 1,500 square feet when mixed and applied with a tank or hose-end sprayer, which is a solid mid-range coverage.
One honest note from the reviews: some users wish it came in a larger size because they found themselves buying three bottles at a time for an acre and a half property. For smaller jobs, the 32 oz bottle is just right.
Lightest Heavy Hitter: At 8 oz total weight, this is easier to carry and pour than the Bonide at 8.6 lbs while still using triclopyr chemistry. The trade-off is less total active ingredient volume per purchase.
Best for: homeowners with 1,500 sq ft of poison ivy or brush who want a lightweight, fast-drying concentrate that won’t break the bank.
pass on it if: you have acres of land — you will run through this quickly and may need the Bonide or Roundup gallon instead.
5. Ortho 0475010 MAX Poison Ivy & Tough Brush Killer Ready-To-Use, 24-Ounce
No mixing, no measuring — just pull the trigger and spray poison ivy on contact. This is the only ready-to-use spray in the lineup and the easiest to deploy.
Buyers report it “works in 4-5 weeks; leaves yellow, then brown, then die,” and many mention it is the only product that finally killed their poison ivy after Roundup failed. At 24 fluid ounces and 1.13 pounds, it is compact and light enough to carry into tight spots along fences and flower beds.
Coverage is non-selective broad spectrum, meaning it will kill anything green it touches — so careful application is a must. One reviewer recommends using a plastic or paper sack to shield nearby desirable plants when roots are tangled with poison ivy. The rainfast window is 2 hours, which is longer than the 30-minute Roundup concentrates but still manageable for a morning spray.
The biggest limitation is the bottle size: 24 fl oz is not much liquid. For a small patch or a few vines, it will finish the job in one session. But if you are tackling a hillside or a large overgrown fence line, you will run out fast compared with a 128 fl oz concentrate like the Bonide.
Instant Use Convenience
- Ready-to-use trigger spray — no mixing or measuring required
- Lightweight 1.13 lbs and compact for easy handling
- Effective on poison oak and wild berry vines that resist other products
Size Trade-off
- Small 24 fl oz bottle runs out fast on medium-to-large patches
- 2-hour rainfast window is longer than the 30-minute concentrates
- Non-selective — will kill any plant it touches
Perfect for: quick spot treatments of poison ivy and brush in small yards or around flower beds where precision matters.
Not for: large acreage or recurring treatments — a concentrate will be far more cost-effective and last longer.
6. Neudorff Weed and Grass Killer, 32 oz Ready-to-Use
Visible results in 1-2 hours — the fastest-acting weed killer in this lineup. It uses a different chemistry from the triclopyr-based products, burning down top growth with fatty acid salts.
Its active ingredients are ammoniated salts of fatty acids (compounds that break down plant cell walls on contact) plus maleic hydrazide (a growth regulator that stops regrowth). The fatty acids burn down the top growth, and the maleic hydrazide prevents regrowth for up to 6 weeks. One buyer says it “works within 1-2 hours; wish it came in larger quantity,” and multiple verified reviews confirm the fast visual result.
The 32 oz bottle is ready-to-use with a sprayer that has usual spray or stream settings, and owners mention the sprayer does not clog. It is rainfast in 3 hours, and the formula does not stain concrete, pavement, stucco, or wood — a real plus for driveway and patio applications. You can resow grass or flowers 5 days after treatment, which is very fast compared to other options that ask you to wait up to 30 days.
One buyer called it a “watered down version of Round Up,” which highlights the trade-off: it kills fast on the surface but may not penetrate deep roots of established woody vines as effectively as the Bonide or Pro Brush concentrates. For young poison ivy and annual weeds it is excellent; for thick, mature brush, you may want something stronger.
Speed Demon: At 32 oz, this bottle is heavier than the 8 oz Roundup concentrate bottle — but that weight is the ready-to-use liquid itself, not a concentrate. You pay for the convenience of fast action without mixing.
Best for: small patches of poison ivy or weeds where you want to see dead plants by the end of the day without worrying about staining surfaces.
it’s not for you if: you are fighting deep-rooted, mature poison ivy vines — a triclopyr concentrate will be more thorough on roots.
Understanding the Specs
Active Ingredients
For poison ivy and brush, triclopyr is the most effective active ingredient. It is a selective herbicide that targets woody plants and broadleaf weeds without harming most lawn grasses. Products that combine triclopyr with 2,4-D or dicamba broaden the weed spectrum. Neudorff uses a different approach — ammoniated salts of fatty acids for rapid burn-down — which works faster but may not penetrate deep roots as well.
Liquid Volume vs Item Weight
These two numbers tell you how much product you are buying and how heavy the container is. The Bonide holds 128 fluid ounces and weighs 8.6 pounds. The Roundup 32 oz concentrate is listed at 32 fluid ounces and 8 ounces item weight. Compare both numbers directly when judging how much product you get and how heavy the container will be to handle.
Rainfast Time
This is the amount of time the spray needs to dry on the leaves before rain can wash it off. The Roundup concentrates are rainproof in 30 minutes — excellent for unpredictable weather. The Ortho needs 2 hours, and the Neudorff needs 3 hours. A shorter rainfast time gives you more flexibility to spray when conditions are good.
Concentrate vs Ready-to-Use (RTU)
Concentrates (Bonide, both Roundup concentrates, Pro Brush) require you to mix the product with water in a tank or hose-end sprayer. RTU bottles like the Ortho and Neudorff come pre-mixed with a trigger or sprayer — pull and spray. Concentrates are more economical for large areas; RTU is faster for small patches but costs more per treatment.
FAQ
Will these products kill poison oak and poison sumac too?
How long does it take for poison ivy to die after spraying?
Can I use these products near my flower beds or vegetable garden?
Do I need to wear protective gear when applying?
Which product works fastest on poison ivy?
Will rain wash away the spray before it works?
Can I use these to kill tree stumps?
Do these products kill grass too?
How many square feet does one bottle cover?
What is the difference between triclopyr and 2,4-D for poison ivy?
Final Thoughts: The Verdict
If you want one dependable pick, the weed and poison ivy killer winner is the Bonide 332 because its three-active-ingredient formula (MCPA, triclopyr, dicamba) kills roots permanently, covers the most ground at 128 fluid ounces, and is safe for lawn grasses. If you want the fastest visible results, grab the Neudorff Weed and Grass Killer. And for quick, no-mix spot treatments around flower beds and fences, the standout is the Ortho MAX Poison Ivy & Tough Brush Killer.
How We Picked
We do not accept paid placement, and we did not hands-on test every unit. Instead, we match each pick to a real buyer and use-case by comparing the manufacturers’ published specifications against the patterns in verified customer reviews — so you get each pick’s real strengths and trade-offs instead of marketing copy.
Sources & Methodology
Specifications: manufacturer listings and product documentation. Review insights: verified customer reviews, as of July 2026. Pricing: not shown on this page (it changes often); check the current price via the retailer link.
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