By Scout Nelson
Spotted water hemlock is a dangerous native plant that grows across many areas of North Dakota. It is one of the most poisonous plants for livestock and people.
Cattle, horses, goats, sheep, and other animals can become seriously ill if they eat any part of the plant, especially the roots, which contain the highest amount of toxin. The risk is greatest during spring, but the plant remains dangerous throughout the growing season.
North Dakota State University Extension specialists encourage farmers and ranchers to inspect hay fields and wet areas before harvesting. They explain that dry weather often forces producers to cut additional hay acres, increasing the chance of harvesting spotted water hemlock without noticing it. Careful scouting helps reduce this risk and protects livestock from accidental poisoning.
Spotted water hemlock grows best in wet soils, including meadows, roadside ditches, creek bottoms, drainage areas, and around cattail sloughs. Floodwater and birds help spread its seeds, allowing the plant to appear in many locations.
Because it belongs to the carrot family, it is often confused with the non-toxic water parsnip. However, spotted water hemlock has reddish-purple streaked hollow stems, deeply divided leaves, dome-shaped flower clusters, and chambered roots.
Extension specialists remind producers to wear gloves when handling unknown plants because the sap may irritate the skin. They also stress that livestock usually avoid the plant when enough forage is available.
During drought or when pasture becomes limited, animals may enter wet areas, pull up young plants, and eat the toxic roots.
The greatest danger occurs when spotted water hemlock is cut into hay. If contaminated hay has already been baled, producers should feed it in a way that allows animals to sort through the forage instead of grinding it into mixed rations. Livestock should never be forced to consume hay that contains suspicious plants.
The best management practice is prevention. Producers should identify infested areas and avoid harvesting them whenever possible. Rotary mowing can reduce seed production when fields become dry enough to mow safely.
Fall herbicide applications using approved products may also help control the plant, but growers should carefully follow all label directions and consider the impact on desirable plants.
For assistance with identification of spotted water hemlock, contact your county NDSU Extension office at ndsu.ag/countyoffice.
Photo Credit: gettyimages-roman-demkiv
Categories: North Dakota, Crops, Hay & Forage, Livestock