By Dusty Sonnenberg, CCA, Ohio Field Leader
From a distance, Palmer amaranth, common waterhemp, and redroot pigweed can easily be mistaken for each other, but proper identification is a key to effective management. Each weed species is a growing problem in Ohio.
Palmer amaranth and waterhemp are relatively easy to separate from redroot pigweed when taking a closer look, because both the Palmer amaranth and waterhemp have smooth stems with no hair on them. Redroot pigweed has fine hairs on the stem.
“It is not critical to separately identify the Palmer amaranth from common waterhemp because the management strategy
is going to be similar for both,” said Jeff Stachler, Ohio State University Extension educator in Auglaize County. “Palmer amaranth and waterhemp are both dioecious plants, meaning they produce separate male plants and separate female plants. That causes a problem from the standpoint of diversity as every flower on a female plant could hypothetically have a unique male plant that pollinated each of the flowers.