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

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.

Best Herbicides for Pigweed

1. Roundup Pro Max – Glyphosate Herbicide

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.

2. Triclopyr 4 – Selective Brush Herbicide

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.

3. Crossbow – Triclopyr and 2,4-D Herbicide

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.

4. Garlon 4 – Triclopyr Ester Herbicide

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.

5. Ortho GroundClear – Glyphosate and Imazapyr Herbicide

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.

6. Dismiss – Sulfentrazone Herbicide

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.

7. Specticle – Indaziflam Herbicide

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.

8. Revolver – Foramsulfuron Herbicide

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.

9. Certainty – Sulfosulfuron Herbicide

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.

10. Tenacity – Mesotrione Herbicide

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.

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.

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.