USDA researchers confirmed that acetic acid is effective at killing some common weed species, including Canada thistle, lamb's-quarters, giant foxtail, velvetleaf and smooth pigweed. Weeds were hand-sprayed with various solutions of vinegar, uniformly coating the leaves.

How do you kill pigweed naturally?

Glufosinate-ammonium or glyphosate are both non-selective weed killers and will kill any plant they come in contact with, so they should only be used in locations where you wish to clear out all weeds and plants.

How do I get rid of pigweed in my lawn?

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.