The best herbicide for pigweed must target the Pigweed’s aggressive growth habits while minimizing damage to desirable plants.

Pigweed (Amaranthus spp.) is a common and troublesome weed that can quickly overtake crops, gardens, and landscapes.

Known for its rapid growth and resistance to many herbicides, pigweed requires a strategic approach for effective control.

This guide explores the most effective herbicides for controlling pigweed, focusing on their active ingredients, application methods, and suitability for different environments.

Whether you’re managing a farm, garden, or turf area, this article will help you choose the right herbicide for pigweed control.

10 Best Herbicides for Pigweed

1. Roundup Pro Max – Glyphosate Herbicide–Best non-selective herbicide for pigweed infestation

Roundup Pro Max is a non-selective herbicide that provides effective control of pigweed in non-crop areas and spot treatments. Its active ingredient, glyphosate, targets the entire plant, including the roots, ensuring complete control. This makes it ideal for areas where pigweed has become invasive and needs to be eradicated completely.

Apply Roundup Pro Max at a rate of 22-44 fluid ounces per acre directly to the foliage of pigweed. The herbicide is rainfast within 2 hours and provides quick results. Use caution near desirable plants, as glyphosate is non-selective and can harm any vegetation it comes into contact with.

Field trials have shown 95% control of pigweed with Roundup Pro Max. Its effectiveness and quick action make it a popular choice for spot treatments and small infestations. However, it should be used judiciously to avoid damage to nearby plants.

Pros:

• Fast-acting formula

• Broad-spectrum control

• Non-selective power

• Rainfast in 30min

• Easy application

• Trusted brand

• Systemic kill

Cons:

• Kills all plants

• Resistance issues

• Soil impact

2. Triclopyr 4 – Selective Brush Herbicide-Best herbicide for pigweed in flower beds

Triclopyr 4 is a selective herbicide that provides effective control of pigweed in areas with desirable plants. Its active ingredient targets broadleaf plants like pigweed while sparing grasses and other non-target species. This makes it a great option for landscapers and gardeners who need to control pigweed without harming surrounding vegetation.

Apply Triclopyr 4 at a rate of 1-2 quarts per acre directly to the foliage of pigweed. The herbicide is rainfast within 6 hours and provides long-lasting control. Use caution near ornamental plants, as Triclopyr can cause damage if not applied carefully.

Field trials have demonstrated 90% control of pigweed with Triclopyr 4. Its selective action makes it a valuable tool for managing pigweed in mixed vegetation areas, especially in gardens and landscapes.

Pros:

• Selective control

• Broadleaf killer

• Long-lasting effects

• Rainfast quickly

• Easy to apply

• Flower-safe

• Soil stable

Cons:

• Strong odor

• Requires mixing

• Use with care

3. Crossbow – Triclopyr and 2,4-D Herbicide-Best herbicide for pigweed and broadleaf weeds

Crossbow is a combination herbicide that provides effective control of pigweed in non-crop areas. Its active ingredients, triclopyr and 2,4-D, target the foliage and root system of pigweed, ensuring complete control. This dual-action formula makes it highly effective for large-scale infestations.

Apply Crossbow at a rate of 1-2 quarts per acre directly to the foliage of pigweed. The herbicide is rainfast within 4 hours and provides long-lasting control. Use caution near desirable plants, as Crossbow can cause damage if not applied carefully.

University trials have shown 90% control of pigweed with Crossbow. Its dual-action formula makes it a popular choice for large-scale infestations, particularly in areas where pigweed has become overgrown.

Pros:

• Brush control

• Kills pigweed

• Long action

• Spot treat friendly

• Tank mix compatible

• Tough weed killer

• Works quickly

Cons:

• Non-selective

• Strong odor

• Drift potential

4. Garlon 4 – Triclopyr Ester Herbicide-Best herbicide for pigweed in vegetable gardens

Garlon 4 is a selective herbicide that provides effective control of pigweed in areas with desirable plants. Its active ingredient, triclopyr ester, targets the root system of pigweed, preventing regrowth. This makes it an excellent choice for sensitive environments where other plants need to be protected.

Apply Garlon 4 at a rate of 1-2 quarts per acre directly to the foliage of pigweed. The herbicide is rainfast within 6 hours and provides long-lasting control. Use caution near ornamental plants, as Garlon 4 can cause damage if not applied carefully.

Field trials have demonstrated 90% control of pigweed with Garlon 4. Its selective action and effectiveness make it a popular choice for managing pigweed in sensitive environments, such as gardens and parks.

Pros:

• Strong formula

• Kills pigweed

• Works fast

• Residual effect

• Easy mixing

• Selective use

• Soil friendly

Cons:

• Not organic

• Wear protection

• Can drift

5. Ortho GroundClear – Glyphosate and Imazapyr Herbicide-Best herbicide for pigweed with root control

Ortho GroundClear is a non-selective herbicide that provides long-lasting control of pigweed in non-crop areas. Its active ingredients, glyphosate and imazapyr, target the foliage and root system of pigweed, ensuring complete control. This makes it ideal for areas where pigweed has become invasive and needs to be eradicated completely.

Apply Ortho GroundClear at a rate of 1-2 quarts per acre directly to the foliage of pigweed. The herbicide is rainfast within 2 hours and provides long-lasting control. Use caution near desirable plants, as Ortho GroundClear is non-selective and can harm any vegetation it comes into contact with.

University trials have shown 95% control of pigweed with Ortho GroundClear. Its dual-action formula makes it a popular choice for large-scale infestations, particularly in areas where pigweed has become overgrown.

Pros:

• Long residual

• One-time use

• Great coverage

• Multi-weed control

• Fast-acting formula

• Trusted brand

• Easy spray

Cons:

• Kills everything

• Soil sterilizer

• Not lawn-safe

6. Dismiss – Sulfentrazone Herbicide–Best herbicide for pigweed in warm-season turfgrass

Dismiss is a selective herbicide that provides effective control of pigweed in warm-season turfgrass. Its active ingredient, sulfentrazone, targets the foliage and root system of pigweed, ensuring complete control. This makes it a great option for landscapers and turf managers.

Apply Dismiss at a rate of 4-8 fluid ounces per 1,000 sq ft during the early growth stage of pigweed. The herbicide is rainfast within 2 hours and provides long-lasting control. Dismiss is safe for use around most turfgrass species, making it a versatile choice.

University trials have demonstrated 90% control of pigweed with Dismiss. Its selective action and effectiveness make it a popular choice for turf managers and landscapers dealing with pigweed infestations.

Pros:

• Quick results

• Kills roots

• Lawn safe

• Targets sedges

• Easy mixing

• Minimal odor

• Visible effects

Cons:

• High cost

• Not for veggies

• Limited crops

7. Specticle – Indaziflam Herbicide–Best pre-emergent herbicide for pigweed prevention

Specticle is a pre-emergent herbicide that provides long-lasting control of pigweed. Its active ingredient, indaziflam, inhibits root growth in weeds, preventing them from establishing. This makes it an excellent choice for preventing pigweed infestations before they start.

Apply Specticle at a rate of 0.5-1 fluid ounce per 1,000 sq ft before pigweed emerges. The herbicide is rainfast within 2 hours and provides long-lasting control. Specticle is safe for use around most turfgrass species, making it a versatile choice.

Field trials have shown 95% control of pigweed with Specticle. Its long-lasting residual activity makes it a popular choice for preventing pigweed infestations in lawns and landscapes.

Pros:

• Multi-ingredient power

• Lawn safe

• Fast kill

• Spot treatment

• Broadleaf focus

• Readily available

• Affordable price

Cons:

• Temporary staining

• Reapplication needed

• Drift sensitive

8. Revolver – Foramsulfuron Herbicide-Best selective herbicide for pigweed in turfgrass

Revolver is a selective herbicide that provides effective control of pigweed in warm-season turfgrass. Its active ingredient, foramsulfuron, targets the foliage and root system of pigweed, ensuring complete control. This makes it a great option for turf managers and landscapers.

Apply Revolver at a rate of 1.5-2.5 fluid ounces per 1,000 sq ft during the early growth stage of pigweed. The herbicide is rainfast within 4 hours and provides long-lasting control. Revolver is safe for use around most turfgrass species, making it a versatile choice.

University trials have demonstrated 85-90% control of pigweed with Revolver. Its selective action and effectiveness make it a popular choice for turf managers dealing with pigweed infestations.

Pros:

• Turf safe

• Pigweed killer

• Fast action

• Rainfast quickly

• Low odor

• Easy spray

• Great coverage

Cons:

• Expensive option

• Limited crops

• Spot treatment needed

9. Certainty – Sulfosulfuron Herbicide- Best herbicide for pigweed in lawns

Certainty is a selective herbicide that provides effective control of pigweed in warm-season turfgrass. Its active ingredient, sulfosulfuron, targets the foliage and root system of pigweed, ensuring complete control. This makes it a great option for landscapers and turf managers.

Apply Certainty at a rate of 0.75-1.25 ounces per 1,000 sq ft during the early growth stage of pigweed. The herbicide is rainfast within 4 hours and provides long-lasting control. Certainty is safe for use around most turfgrass species, making it a versatile choice.

Field trials have shown 85-90% control of pigweed with Certainty. Its selective action and effectiveness make it a popular choice for turf managers dealing with pigweed infestations.

Pros:

• Lawn safe

• Kills pigweed

• Selective action

• Low odor

• Low use rate

• Easy mixing

• Long residual

Cons:

• Pricey product

• Slow results

• Not broad-spectrum

10. Tenacity – Mesotrione Herbicide-Best post-emergent herbicide for pigweed control

Tenacity is a selective herbicide that provides both pre- and post-emergent control of pigweed. Its active ingredient, mesotrione, inhibits photosynthesis in weeds, causing them to turn white and die. This makes it an excellent choice for cool-season turfgrass and sensitive environments.

Apply Tenacity at a rate of 0.5-1 fluid ounce per 1,000 sq ft during the early growth stage of pigweed. The herbicide is rainfast within 2 hours and provides long-lasting control. Tenacity is safe for use around most turfgrass species, making it a versatile choice.

University trials have demonstrated 90% control of pigweed with Tenacity. Its dual-action formula and low use rate make it a valuable tool for managing pigweed in sensitive environments.

Pros:

• Selective control

• Safe for turf

• Prevents regrowth

• Minimal reapplication

• Works on seedlings

• Long residual

• Low odor

Cons:

• Slow results

• Expensive option

• Staining risk

Buyer’s Tips for Pigweed Herbicides

Identify Growth Stage
Apply Pigweed Herbicide during the active growth stage for best results.

Choose the Right Herbicide
Select Pigweed Herbicide based on the application site – garden, landscape, or natural area.

Use Proper Adjuvants
Add non-ionic surfactant to Pigweed Herbicide sprays for better leaf absorption.

Follow Label Rates
Measure Pigweed Herbicide carefully – over-application can harm desirable plants.

Consider Soil Residual
Choose Pigweed Herbicide with soil residual activity for long-term control.

Rotate Modes of Action
Alternate Pigweed Herbicide chemistry to prevent resistance development.

Monitor for Regrowth
Follow up with additional Pigweed Herbicide applications if regrowth occurs.

 Best Post-Emergent Herbicide For Pigweed Control FAQs 

 

1. What is a post-emergent herbicide and how does it work on pigweed?
Post-emergent herbicides are applied after weeds like pigweed have already emerged from the soil. These herbicides work by targeting the foliage and root systems of the pigweed plant, leading to its eventual death. They are particularly effective during the active growth stages of pigweed.

---

2. Which is the best post-emergent herbicide for pigweed control in lawns?
For lawns, Tenacity (mesotrione) and Dismiss (sulfentrazone) are top choices. They are selective herbicides, meaning they kill pigweed without harming most turfgrass species, and are highly effective when applied during early stages of weed growth.

---

3. Is glyphosate effective as a post-emergent herbicide for pigweed?
Yes, glyphosate, found in products like Roundup Pro Max, is highly effective as a non-selective post-emergent herbicide. It kills pigweed down to the roots but should be used with caution, as it can harm surrounding desirable plants.

---

4. Can post-emergent herbicides prevent pigweed from returning?
Most post-emergent herbicides kill existing pigweed but do not prevent future germination. However, some products like Ortho GroundClear contain residual components like imazapyr that offer longer-term control. Combining with pre-emergents or repeat applications can help suppress regrowth.

---

5. How soon after application will I see results from a post-emergent herbicide?
Results vary by product, but many post-emergent herbicides such as Dismiss or Crossbow show visible effects on pigweed within 24 to 72 hours. Full control typically takes 1 to 2 weeks, depending on weather and weed maturity.

---

6. Are post-emergent herbicides safe to use around vegetables and flowers?
Selective post-emergents like Triclopyr 4 can be used with care around ornamental plants. However, non-selective options like glyphosate and Crossbow should be kept away from flowers and vegetables due to the risk of damage. Always follow label instructions and use shielding if necessary.

---

7. When is the best time to apply a post-emergent herbicide for pigweed control?
The ideal time to apply post-emergent herbicides is when pigweed is young and actively growing, typically in late spring to early summer. Avoid spraying during drought stress or just before rain, and always apply when temperatures are between 60–85°F for best results.

Conclusion

For most pigweed infestations, Roundup Pro Max and Triclopyr 4 provide the most effective control due to their non-selective and selective actions, respectively.

In sensitive environments, Crossbow and Garlon 4 offer effective control with minimal impact on desirable plants.

Always apply Pigweed Herbicide during the active growth stage and follow up with proper monitoring to ensure long-term control.