Plant Profile: Amaranthus palmeri

Palmer amaranth, often referred to as Palmer pigweed, is a highly aggressive and rapidly growing weed that has emerged as a significant challenge for vegetable and row crop farmers in the southern United States in recent years. This species has also spread to regions in Europe, Australia, and beyond. Known for its remarkable growth rate—up to an inch per day—Palmer amaranth thrives in hot conditions and can withstand extremely low rainfall.

This summer annual plant typically grows tall and erect, with branching stems that can reach heights of 6 to 8 feet, and in some cases, even exceed 10 feet.

Palmer amaranth exhibits a dioecious reproductive system, meaning that male and female flowers are found on separate plants.

Notably, this species has a rapid germination rate and a robust root system, allowing a single plant to produce as many as 500,000 seeds. Effective management strategies, such as cultivation and flaming, are most successful when applied to plants that are under 1 inch in height.