Mimi Broeske, Nutrient and Pest Management Program
Use the quick 3 steps in this two-page guide to determine what species of Amaranthus (pigweeds) you have. The guide also provides information on managing Amaranthus sp., documented herbicide resistance in Wisconsin for Palmer amaranth and waterhemp and a list of additional resources.
https://ipcm.qa.webhosting.cals.wisc.edu/download/pubsPM/AmaranthusWeedID.pdf