Two new pigweed species including Palmer amaranth (Amaranthus palmeri S. Watson) and tall waterhemp (Amaranthus tuberculatus (Moq.) Sauer), which are commonly found in midwestern and southern United States, have been identified recently in the Northeastern (NE) region. These two pigweed species are considered highly problematic in other U.S. regions and can cause significant grain yield losses in various field crops. Some of these newly invaded populations of Palmer amaranth and tall waterhemp in the NE region have also been found resistant to glyphosate. Rapid spread of these new pigweed species with evolved resistance to glyphosate can pose a serious management challenge for producers in the NE region.