Mowing can suppress spiny pigweed seed production, but even beat-up plants can still occasionally produce seed. Applying products with dicamba (at a rate of 1 lb ai/A) or Crossbow® (2 to 4 qt/A) are effective at controlling spiny pigweed.

How do I kill pigweed in my lawn?

Sprays will be most effective on plants less than 4 inches tall. A ready-to-use, glyphosate-based herbicide kills most pigweed plants. Spray all the plant surfaces until wet, and target pigweeds precisely. Glyphosate will kill other plants it contacts.

Why is pigweed so difficult to control?

Why is pigweed so difficult to control? These two pigweeds are difficult to control, mostly due to their herbicide resistance and fast growth (especially in hot weather). Often, these pigweeds are not noticed until they are seen growing up over the crop canopy, especially in soybeans.