Fourth Confirmed Detection in Montana
In August 2025 one Palmer amaranth plant was found growing near a grain bin in Hill County. The plant was removed from the site and further monitoring of the site is planned. This detection follows one in Carter County in 2024, and detections in 2023 in Daniels and Toole Counties. To date fewer than ten Palmer amaranth plants have been found in Montana, and all were removed from their sites prior to seed production. This plant is not known to be established in Montana.
Be on the lookout for Palmer amaranth (Amaranthus palmeri) and its close relative waterhemp (Amaranthus tuberculatus). Both are pigweed species that have developed genotypes resistant to most herbicide modes of action. If they become established, these two species will have a large economic impact on Montana agriculture. Both weeds have the potential to establish in warm season crops such as corn and millet, and also irrigated sugarbeets, cereals, and pulse crops.
