Palmer Amaranth (Amaranthus palmeri) is an aggressive, invasive weed native to the southwest region of the United States and northern Mexico. It has become a significant pest problem in the southern US soybean and cotton region. This plant is resistant to many herbicides including glyphosate, which makes it a difficult pest to control once it becomes established.
The plant is highly adaptable and is able to produce 100,000 seeds per plant. Its high growth rate and height (6 feet +) can cause significant yield losses and harvesting issues. If the plant is allowed to seed out, control will be difficult. Early detection and removal before seed heads form is best to combat this plant.
In Ohio, it has been found on multiple sites, with most eradicated before seed formation, however, there are a few sites that have more severe infestations. The introduction of this plant can come from contaminated farm equipment, livestock feed, or from contaminated seed sources outside Ohio where Palmer Amaranth is present. It can come in from any seed source, including wildlife food plot mixes and deer feeder food. It is recommended to have your seeds tested by the Ohio Department of Agriculture to ensure noxious weeds are not present before planting them on the properties that you manage.
If Palmer Amaranth is suspected on your property (there are native look-a-likes), contact any agricultural related office to report and get experts on site to confirm. There are many websites devoted to its identification and control; become familiar with this plant, as it is likely headed our way.